Top 20 2001 GMC Sierra 2500HD Questions & Answers

Wiring diagrams. https://www.google.com/search?q=2001+gmc+2500hd+headlights+wiring+diagram and https://www.google.com/search?q=2001+gmc+2500hd+headlights+wiring+pinout Plus https://www.alldata.com/diy-us/en ..

question edited for clarity typos and spelling, break/brake, 'peddle/pedal. Question move to model category. Incorrect wiring or bad earths on the trailer (common issue) https://www.google.com/search?q=2001+gmc+2500+hd+trailer+wiring+diagram

HI, Check the relay box under the hood - remove the relay related to parking lights and see if it goes out. If it does, replace the relay. I've had these go bad in the past and get stuck in the on. Doug

do a compression test to eliminate valves and valve seat insert could be a problem hydraulic lifter causing the miss

Check alternator output against specs. I suspect that the issue is with the belt not being properly lined up with the pulleys

If this is an old starter then it is going out. It is not engaging with the fly wheel and that is the "running sound" you are hearing. It is also the reason that it is not starting the vehicle for you. The shaft is not coming out and engaging all of the time. Long and short of it is replace the starter and all should be good

check/clean MAF sensor on air inlet

did you try Allison dealer

Hi Lone Ranger, The first link offered has information to set you up US Diesel Parts Fuel Pumps Injection Pumps and Injectors GM Duramax LB7 . Now on to the location. Here is a quick feed to watch duramax cp3 pump swap . Lets finish with this gentleman's input and contribution. Duramax cp3 high presure fuel pump removal . This will provide a look and see distant generalization of what you may be getting into and some live experiences of those who did. Fare. Well.

arrow points to front of motor

Cylinder 8 Misfire Detected pcm find a misfire on cylinder 8 hope it helps

Buy a NEW line and put it back on from where you take the old one off from

Do you have DIC? (Driver Information Center). If you have controls on the steering wheel you can change the program to keep the headlights and the interior lights on. Maybe you can borrow an operators manual if you don,t have one. Simple procedure. Keep us posted, good luck.

Put it on a TOW Truck and take it to the dealer to fix the problem. Hopefully it is the warning lights crook not what they are telling you is wrong

Read the workshop manual and it should give you the correct instructions

Glue the vents in

sounds like partial short in headlight switch

replace the serpintine belt and check the tensioner

check the gear linkages may be loose.

fuel level sensor or gauge intank is defect two little metal finger touching the resistor are worn sometime it touch sometime not.