20 Most Recent 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

It sounds like your alternator might be starting to go bad and the Battery Light is coming on because it is not charging the battery correctly. Have your Alternator checked with a volt meter, it should be reading 13 to 14 volts if working correctly. If not, replace your alternator.

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

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

Glue the vents in

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

replacing the fuel pump on this truck, requires the fuel tank to be removed. the fuel pump is installed in the fuel tank. you can either drop the fuel tank or remove the truck bed to gain access to the fuel pump

check/clean MAF sensor on air inlet

did you try Allison dealer

arrow points to front of motor

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

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.

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