Duration 27:40

GM Fuel Pump Relay Testing

by ScannerDanner

1 654 079 watched

6.4 K

Published 23 Aug 2012

The vehicle being tested is a 1999 Chevy Suburban with no fuel pressure. This truck had a new fuel pump installed and still did not have fuel pressure. In this video I will show you how to troubleshoot this entire fuel pump electrical system, including the fuel pump relay, wiring and computer. Engine Performance Diagnostics chapter 3 page 26 Symptoms - no start with good spark - no fuel pressure - no trouble codes Fix - repair wiring to the fuel (new pump was wired backwards Tests shown - how to test a fuel pump relay in a power distribution box. - power side switched circuit design description and operation. - Fuel pump power and ground testing. - how to manually jump a fuel pump from the fuse box - how to test a fuel pump relay - relay pins (what each one does and how to test them) - how to verify computer control of the fuel pump relay - bias voltage (what is it, how to use it, how it can cause misdiagnosis when using a voltmeter) - wiring diagram review of a fuel pump relay circuit in my classroom (a ScannerDanner premium segment) - how to measure fuel pump current - what sets a fuel pump relay control trouble code Tools used - ATD Tools 5519 Auto Ranging Digital Multimeter https://www.jbtoolsales.com/atd-tools-5519-auto-ranging-digital-multimeter-with-protective-holster#oid= 1014_1 - incandescent test light https://www.jbtoolsales.com/otc-3633-mini-circuit-tester#oid= 1014_1 - backprobing pins AES' Electronics Accupuncture Probes http://www.aeswave.com/cart.php?m=affiliate_go&affiliateID=60df1b5cf6e5582af6ff81c728f42d0d&go=http://www.aeswave.com/AES-Electronics-Accupuncture-Probes-p9474.html Playlist - (Chapters 14, 15,16) Fuel Delivery and Fuel Pressure Testing /playlist/PLAFYVCyenqcrstVqfSc1PCbQ1pebuNIO6 Related videos - Fuel Pump Electrical Circuits Description and Operation /watch/0DeH-xrftqRfH - Fuel Pump Relay Problem /watch/Qy4Tq_omjECmT - How to test and fix a PGM-FI main relay on a Honda, Acura /watch/AK8RoT-pQ5XpR - How to test an electric fuel pump (1997 4.3L Chevy Blazer CPI) /watch/4lqs316YQjyYs - Fuel pump electrical circuit diagnosis (no fuel pressure testing) GM /watch/UsSjpZ3YNgZYj For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book. Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium https://www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial. On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere! Disclaimer: Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

Category

Comments - 806

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@manelishi13 months ago You answered my question before i could ask and yes i' m subscribed to sd prienun. Learning your insight and methods i was instantly going to say, . ...Expand 1
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@xtilt118 years ago 2004 gmc savana 3500 cutaway, with a 15' box. No start, no pressure. Was able to jump the correct pins (you explained very well) and send constant . ...Expand 2
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@williamfolk587812 years ago Great example of why when diagnosing an electrical issue a test light and a meter should be used when trouble shooting. Thanks for the video, very informative! 3
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@paulmac33076 years ago Paul, i' ve immersed myself in *your videos cam/crank sensors, hall effect pull up/dn testing, mostly inan 01 i30 no start for weeks and you' ve impressed me to no end. But **this lesson here has inspired me so much so that i *had to write to commend you on your style, brilliance, tenacity and skill! Even more thank you for your technique in imparting knowledge to the layman now so rarely found i' m sure. I' m an faa certificated airframe & powerplant mechanic since 16 years old (63 now, commercial pilot and instructor since 1974 and tow truck driver shade tree automotive wrench too, admittedly **not even close to your realm - learjets vs. Maserati = two different beasts. But where does one start explaining your passion? Brilliant teaching technique? Abundant resource of the mind? Vast stores of vital bits of info that just. I mean. And you produce smooth relevant attractive media seeming to come from out of nowhere like this: pwd side circ bias vltg and backprobing ir drop right **there in the trenches with simple test light and vom! And for free? I mean you are so cool - meticulous white board drawings, manuals books, well i just wanted to say thank you for being so kind to us out here. Your students i hope will be touching my vehicles out here and you' ve restored my confidence raising my opinion of auto wrenches in general. I hope they appreciate your stern yet friendly demeanor, temperance, ethical mentorship and carry your legacy paying it forward and so on for quite some time. There will never be another sage like you, and at such a young age. Amazing. Thank you! Paul the pilot, san diego. ...Expand 4
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@zimgir794 years ago Great job on describing the bias voltage! You took something that could be extremely confusing and made it fairly simple. 4
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@alexandertrossen55617 years ago Who is this guy! Great instructor and definitely a passionate person. Thanks scanner dan, you saved me some money on my diagnostic and i learned something really cool. 8
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@ScannerDanner12 years ago Thank you so much! What a great comment. This bias voltage is cool when you know how to use it. It is a major time saver forwiring problems for sure. Nice to know that you appreciate the material. 6
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@guardiansunite50136 years ago The effort you put in to this video and your teaching skills are amazing. Thank you very much for doing this. 6
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@johnchristopherson271810 years ago Awesome! I have been in the automotive repair industry since 1983 as a tech and as an instructor, you did a very good explanation of the bias voltage. 18
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@USAPatriotMan3 years ago This is what reallooks like! Great job! 2
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@memo03leo5 years ago Thank you for your time in instructing us on how to diagnose a fuel problem! 1
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@KennyDPhotography8 years ago I appreciate the attention to detail andanalysis. I' ll definitely be checking out more of your videos. 1
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@PUNTO8SERVICE12 years ago Got to say you are a great teacher and i hope your students are very happy having you there with them good luck and god bless you!
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@randyfrazier57252 years ago Poor guy had no business rewiring the pump. We have a saying in the electrical trade that comes to mind. It goes like this: " 1 wire hook up, 2 wire f* up, 3 wire drag up! " awesome job scanner danner.
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@billrimmer55966 years ago This is why i have scanner danner premium on his website. Even if he never makes another video, how can u thank him for the humongous library chocked full . ...Expand 26
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@matyAnonymuS11 years ago Thanks for the reply! I asked my mechanic; the dist cap and ignition components have been checked, its all good. The whole distributor is 18 months old. . ...Expand 1
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@MojoPup7 years ago Scannerdanner, thanks for a great video! I appreciate the detailed explanations and diagrams. I work in the medical device field as an electronic tech . ...Expand 2
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@mikechiodetti67376 years ago Having the test light and/or the current meter connected are great tools working together when locating an intermittent pump or current feed problem. I good video! Didn' t know about the bias voltage in that gm circuit. ...Expand 1
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@35rem809 years ago We bought our truck used and have this exact wiring mess. Thank you so much for this video brother. It helped and helped a lot! 1
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@jeremyshanks693710 years ago Great video. I like the comment on the lean pop through the intake at snap throttle. I have been using these videos to troubleshoot electric fuel pumps . ...Expand 2
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@Bewildermint10 years ago High praise for this video! Danner is thorough and provides all the necessary background to understand what' s going on. Great diagnostic technique. Very professional! Thanks. 1
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@danielmaher72946 months ago Dan, you are awesome! Excellent teacher. I have fixed two of my chevy truck' s watching your videos and felt confident because it makes sense in my mind. Thank you so much!
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@grantlarmstrong12 years ago What a great video and great explanation. Having some electrical background helps too. It definitely helps why one reads voltage duringwhen you wouldn' t expect to. 1
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@mrexecutive112 years ago Scannerdanner is the master of electrical circuits, wow! Keep these case studys coming! 1
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@samspade861210 months ago Outstanding video, my 99 suburban wouldn' t start after a long drive. It finally started but i' m going to do the checks thanks to your video. Much appreciated.
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@WallaceRoseVincent10 years ago Great video! I am an electrical engineer and you explained the bias circuit well. I think you can say the 12 volts is across the high ohm internal resistor . ...Expand 4
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@MyStone8812 years ago I took 3 years of automotive classes in high school. I now sit in front of a monitor 10 hours a day for a living but never lost my love in fixing cars. . ...Expand 3
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@glendayle7 years ago Thanks for this video. I' m just a home wrench turner. I' ve run into this situation before and have in the past preferred to use my volt meter over . ...Expand 1
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@j818518 years ago Sinking or open collector transistor. Used widely in industrial control, jumped the fence at gm and invaded our cars when computers became standard. Coil . ...Expand
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@moosemcguirk16402 years ago Fantasticim pretty sure its going to fix my problem where the previous owner bypassed the relay to make a pump run continuously instead of diagnosing. 1
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@dirtyboy83366 years ago I' m learning so much from
this guy i just need tools
to get me started on working
on my own car. Thanks for
all the good knowledge. 1
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@rogernegrete83764 years ago Your a good teacher, you get off teaching, if one would listen to your video 10 times it would just click just like that little piece of plastic your working transistor and it clicks, sending that current in a controlled flo to open the pump which pumps
fuel to whatever system
you have. ...Expand 1
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@harstine42011 years ago A great teacher, reminds me of my school boy days at denver automotive and diesel college, i am old school. Thanks dan! Keep on teaching the youngers.
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@cockasorrus74753 years ago Wow! Just learned a whole bunch of excellent info. Watching your awesomely produced video! Just a fantastic job on every level! Thank you!
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@wtfhappened6617 years ago Wow. You guys deserve medals for your painstaking film!
i still don' t quite understand why the pcm needs that bias voltage - which makes id="hidden26" a 1950 test-light superior to a modern, 10-megohm meter - but that discovery at the back reinforces what i tell people about using old shops instead of start-ups.
i actually encountered the same problem with 110v in my elks club. When i converted old-style potentiometers and mag-ballasts to modern electronic units, they wouldn' t dim. Sure enough, some moron had wired white-to-black & black-to white!
lol. ...Expand 2
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@GRUSSNewton12 years ago I have been caught out using a multi meter in the first part of the video. Excellent explanation as usual paul!
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@ericgilbert71944 years ago I very much appreciate this video! Although it wasn' t the issue i was experiencing at the time (fuel pump workingit did get my brain gears in motion. I had removed the bed to change rear cab corners, and had just loosely placed the ground bolt back in place, that just happened to ground the bed lights and the fuel pump. After finding no continuity between the pump lead ground and the frame, the a-ha moment smacked me like a freight train. A very good feeling freight train: subbed, and thanks for the content!. ...Expand 3
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@alexisfrancisco149112 years ago This guy is good. He is very informative even when its technical, i somehow understood even when im just laymen. I open this video because my hyundai starex . ...Expand
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@pabloarevalodelaguila87674 years ago Que buen diagnostico, es impresionante lo que usted hace con los vehculos. 1
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@amandabryson168911 months ago I have been learning so much from people' s hands-on videos. Thanks for letting us pic ur brain.
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@mohawkmike14212 years ago Danner, you just made my day with that biased voltage explanation. Awhile ago i was working on a relay circuit and my voltmeterthis and it threw me for hours. Nobody i talked to ever had an answer. Like a christmas present lol thanks. Hope santa brings you one of those lisle relay test jumper kits. The dink that stabbed, cut and miss wired that pump should get coal. ...Expand 1
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@halomotto715810 years ago Thanks scannerdanner! I am really enjoying and learning much from your straight forward videos.
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@dariomendoza68925 years ago Awsome video sir i have never messed much with electricty but watching this video inspired me to try to { tackle my no power to the fuel pump relay wire } on my car! 1
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@fivefortyeye540i12 years ago And the oscar go' s to, scannerdanner! For best supporting instructor! Now i get it, i needed that visual. Lol that buick cooling fan relay has been . ...Expand
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@NDJones-th6jq7 years ago You saved my butt showing bias voltage. I was making check on my 1998 5. 7 vortec and showed 12. 24 v. This was messing with my head and i was thing something . ...Expand 1
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@RdustinJ11 years ago Thanks for the help. Changed fuel pump, strainer, and fuel filter. Starts right up every time!
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@jamesduca17562 years ago Omg, i' ve been scratching my head on this for ever! Thanks.
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@jonboy54512 years ago Wow. This is a phenomenal video, with a very thorough explanation. I always wondered how gm and chrysler could monitor relay circuits and throw a p1x id="hidden33" code for a relay coil (control) failure. Im sure other manuf. Do as well, ive only seen it on gm and chrysler. Thank you very much for this video. I don' t use a test light as often as i probably should, usually use a dmm. I' ll have to pull out the test light more often. ...Expand
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@AlfredoGarcia-ej9rp4 years ago So glad i came across this video. Subscribed right away, the way you explain stuff and the education you give is so good. A lot of info but very clear thank you.
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@martinmoffitt47024 years ago " i don' t make themore like you explain em' priceless thank you for your talents!
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@Micromaster3332 years ago Thank you don' t know how much you help me right now to learn how to figure this out i really appreciate it fella.
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@dennissmith765711 years ago I have a ' 94 silverado i have to work on sunday apparently they changed a dead battery and i no gas since. I checked it out a while back and pump isn' t . ...Expand
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@rebelyell46796 years ago The oil pressure sensor is also a source of power for the fuel pump, while the engine is running. This is done to keep you going in case of a fuel pump . ...Expand 8
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@ventureelect12 years ago Always look forward to seeing your videos. Great stuff dan, thanks.
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@vencentbauer8 years ago Great video i have messed that up a bunch of times test light is only way to check them i finally bought tge lesley relay extentions do all my testing with them very handy. 1
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@BMTroubleU12 years ago It was only my 1990 mh barina, aka suzuki swift, picked it up from a mate for $100. I was more worried about the branding of a paper clip shape singed . ...Expand
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@sensign6718 years ago Great analization. By the author. Thanks for the post, and look forward to any further ones. You guys are the electrical kings!
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@VIPReefAquariums6 years ago I wish you were in my neck of the woods sir! Awesome mechanic!
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@steveberliner7747 years ago Excellent job! Great teacher - well spoken - complete. 2
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@s1ight4 years ago Genius, this guy should be an engineer designing this stuff. Seems more intelligent then me and most of the people i went to school with for mechanical engineering.
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@noejitta9 years ago It definitely does, and i completely understand your are teaching ever aspect of how to test. Which is excellent, i really appreciate your channel. Just wanting to make sure my thought processe was right. Thanks again.
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@brt-jn7kg5 years ago Pay attention this is a mechanic at work he is a maestro he is a professional. 1
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@stevelong77023 years ago Thank you so much. I love your videos and they are real educational. I was able to fix my 96 gmc c1500 with this video. I have made a folder, and have . ...Expand
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@78monteman11 years ago Thank you for posting this. Bias voltage who would have known. Helped me out a lot. Still not receiving the correct voltage from the pcm. Off to figure that one out.
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@johnerazo22332 years ago Thank you! Good teaching the way a teacher should teach. Keep up the good work.
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@noelconroy36477 years ago Thanks for sharing valuable information on regulator pressure.
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@ScannerDanner12 years ago @punto8service thank you so much for your kind words. And may god bless you too!
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@Joel11226412 years ago Thanks danner for sharing your expertize. I' ve been looking very hard for clear instructions on by-passing the security fuel shut off on 20 chevy . ...Expand 2
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@SteveRobReviews12 years ago @scannerdanner the best parts of your vids are the ability to explain a function exactly although you do need some basic understanding to absorb it. The . ...Expand
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@AlForte133 years ago Thanks @scannerdanner great explanation, i know i have a bad pump (not crossed wires) i need to figure out how to change the pump.
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@yonivazquez86149 years ago Thank you, danner for all your videos.
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@sdenney897 years ago Damn dan, your flippin awesome! I' m a 30 year mechanic and wish i had your powers! I amaze myself at my abilities every day? Jus wished i had your drive n, desire to be the best? 6
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@needachan12 years ago I really enjoyed this video. It was very helpful now i know where to look at for the fuel relay. Thanks again.
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@ScannerDanner12 years ago I literally just laughed out loud. Thank you and merry christmas! Now you can start looking for it and using it to your advantage.
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@teristoledo11 years ago Great video paul. Like all of them. I studied 2 years in school and now i spent hours and hours in front of my laptop wathching them. I wish i find the . ...Expand
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@JB-Eight7 years ago This video, saved my but, helped me determine, i didnt have a ground. It would be better if he took out all the diagrams/graph part, but all in, need id="hidden47" to add, a reminder if you took the bed off a pickup for installation of pump rather then the droppingvthe tank, must re-connect, the ground wire to the frame where you unpluged the tail light wires for the bed removal, or you end up looking at this video - simply for a quick test after install of new pump, with the bed still off. Before installing the bed. All mechanics check their work. ...Expand 3
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@fomocotech8 years ago Mr. Danner,
may i have a link to your book? For what its worth, your videos are way more informative than most of the factory vw, audi, or ford classes i have been to.
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@halcyon10309 years ago You are quite a rocking dude for serving the community of diy and interested on lookers. I am facinated and intimidated by modern electrical systems id="hidden49"and the computers that control them. Could you recommend a primer book or do your films teach an old school guy that does alright as a parts changer but wants to really have the equivalent of a formal education in auto mechanics. I may yet switch careers but need to become updated from non-computer controlled engines. ...Expand
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@morrie300011 years ago Hey danner i have the 97 chevy express i replaced the pump hooked wires up correctly pump wasn' t coming on so i got under the vehicle with a tester . ...Expand 2
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@mechanicshaficug94564 years ago Thanks for the great explanation ireally appriciate that u introduced to me the basic wiring concept.
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@8_track7 years ago Hi scanner danner, great video! I learned a lot, thank you. I have a 1997 c2500 5. 7, bought new, cared for, now has 229, 0 miles and looks a drives like . ...Expand 3
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@wyattoneable7 years ago I' m here from the " chap 16 fuel pumpvideo because i own a similar vehicle. Great stuff here paul.
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@allanhongemail4 years ago Thank you very much for a great video on a fuel pump and replay.
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@Mr572u10 years ago Enjoyed it, understood it, and i still like the access hole in the bed floor too!
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@georgebonney906 years ago This was a great video, i really enjoyed it and learnedu mr. Danner.
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@kennydewilde11 years ago Very nice video! Especialy the bias voltage this misleaded so bad, good job guys keep it up grtz from belgium.
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@RdustinJ11 years ago Ok. I' ll try the jump start and see how that works. I need to get a fuel pressure gage anyway in case something like this happens again. Appreciate your info and help. Thank you.
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@sanduskyserpents12 years ago Great video. I have to do this same thing in class tomorrow and this visual aid was a great help!
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@henrys51557 years ago Well done, you obviously know your stuff!
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@giftofnile6 years ago Thank you, scanner dan for a great video, question did you have your ignition key on when you measured the amps?
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@wai2machine82310 years ago Also try jumping power to the ground signal on the relay. This fixes it 99. 9% of the time.
pro tip.
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@superk45622 years ago Minute 23. That is so funny! A long time ago, one of my brothers (brother 1) installed a new radio in his truck. Having not followed the installation id="hidden53" at all! He connected all of the speaker wires (positive and negative) together. When there was no sound, he called my other (brother 2) to help. Brother 2 discovered the discrepancy, and now the infamy of his mistake lives in family legend for evermore. Anytime i' m discussing electrical stuff with brother 1, he' s always eager to have brother 2 come help. Names withheld to protect the guilty. ...Expand
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@ScannerDanner11 years ago Yes, we just moved from homestead to crafton. We never closed down thanks! 1
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@fermate19917 years ago Iam learning a lot from your videos. Thank you very much.
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@PaulCTownsend9 years ago Great info paulmerry christmas to you all and your brother to. 1
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@olruss65134 years ago Will, when you get tired of wrenchin it, any auto tech college would be proud to make you an honored instructor, your alright!
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@armandonika8 years ago The one who changed the pump pretty sure was a hell of a mechanic. 11