Whack Electrical Issue - Help!

[greenmountainhbf]

So, we've got a 2008 GMC Sierra 2500HD. Its got a good chunk of miles and wear and tear on it (it is used for plowing, hauling, etc.). Currently at 110k miles, but the issue started at about 80k. Here's the deal, and no, I am not exaggerating.

 

Turn on right turn signal - hood sensor goes off (and signal works)

Turn on high beams - windshield washer fluid comes out (high beams also work)

Beep horn - fog lights turn on (and horn beeps)

A majority of the time, the gauges do not work or work properly.

Sensor that washer fluid is low is constantly chiming - even if full.

Apparently, it's in need of an oil change - always.

 

The truck was bought used in 2011 with 20k miles. It was used around someones house for occasional plowing. Not a flood vehicle (which it what we thought) - or not a reported flood vehicle.

 

Has anyone seen or heard of these problems before? The truck is still worth a good wad of money, but the current highest trade in offer is $6900, which is a joke. It's got to get fixed. Willing to entertain any thoughts/ideas/etc., especially if we can fix it ourselves...... ugh.

[2500HD2001]

Is it cold where you are my find had a similar problem and it turned out there was moisture in the comp and ice had formed and was making problems

[waumo1]

Check all your ground cables for good connection. Bad grounds can set the whole vehicle crazy.

[NitroCherokee]

Sounds like a definite ground issue, start at the battery cable, then the ground strap from the engine to body. Also a good place to look is the grounds on the frame just behing the left front tire good place for corrosion

[gmtech4]

Sorry buddy , you can't fix this from the Internet , doesn't matter if anyone has had this happen , it's happening to you now , you need a schematic (service information ), knowledge how to read it and experience on how to self diagnose this concern on a computer controlled veh ,

 

Take it in , post back what is was cuz no one does

 

Good luck , you have a serious problem .

 

It's been goin on for 30k miles ???? Sweet jebus dude

[ujtruck]

Sorry buddy , you can't fix this from the Internet , doesn't matter if anyone has had this happen , it's happening to you now , you need a schematic (service information ), knowledge how to read it and experience on how to self diagnose this concern on a computer controlled veh ,

 

Take it in , post back what is was cuz no one does

 

Good luck , you have a serious problem .

 

It's been goin on for 30k miles ???? Sweet jebus dude

 

+++1 Rob

 

all above ++ you must know how to perform voltage drop test to isolate defective circuit - and this could be simple loose ground cable issue

[greenmountainhbf]

Check all your ground cables for good connection. Bad grounds can set the whole vehicle crazy.

 

Already done. At least the grounds on the frame were checked. Usual mechanic laughed... told me the solution was a brick on the gas.

 

Looks like it'll go to the GMC dealer... and my wallet will be immediately thinned.

[00Silverado4x4]

Did you check the engine block ground?

[gmtech4]

This kills me .... Grounds just don't get loose people.

 

So stop suggesting it already

[SierraRover]

Well, my new (500 miles) 2014 Sierra 1500 has a whacky problem too -- the inside lights flash briefly when I apply the brakes or put on the left turn signal, but only when the headlights are on. So I have the two lights covered with 100 mph tape right now so I can drive at night. Anyone else have this problem? Thinking it might be a grounding problem in the back left tail light, but if I can't fix it with a quick function check there, it'll have to go to the dealer for warranty. (To Govtech4's comments on grounds not coming undone, I agree it is less likely today than in yesteryear, but in this case it could even be an initial manufacturing slip-up, because it did it from the day I bought it new three weeks ago).

[gmtech4]

My point was that how can anyone know where the grounds are without a schematic and vehicle zoning knowledge ..... They can't ,

 

Well, my new (500 miles) 2014 Sierra 1500 has a whacky problem too -- the inside lights flash briefly when I apply the brakes or put on the left turn signal, but only when the headlights are on. So I have the two lights covered with 100 mph tape right now so I can drive at night. Anyone else have this problem? Thinking it might be a grounding problem in the back left tail light, but if I can't fix it with a quick function check there, it'll have to go to the dealer for warranty. (To Govtech4's comments on grounds not coming undone, I agree it is less likely today than in yesteryear, but in this case it could even be an initial manufacturing slip-up, because it did it from the day I bought it new three weeks ago).

As for your concern , you have warranty and leave the truck with them , road test with a shop Forman or higher