Truck Possessed?

[doo dah]

This morning I headed out to take my Polaris to the shop and the truck acted very strange. Wipers won't work, checked fuses and they are good. Right headlight works but left does not. When I do turn the lights on the reverse lights stay on and the truck won't shut off when I turn the ignition off. If I turn off the headlights the truck will shut off. I am getting random trouble codes every time I check, the only constant that I can't clear is p0000. I went though the fuse box looking for wiper, headlights, etc...and all fuses are good. Could the left light be shorted out and causing the issues? I have LED bulbs that I got from a vendor on PSA. At first I thought trailer might have a short so I disconnected it but still having issues. I just locked the truck with the remote and the panic alarm came on and the remote would not unlock the truck or turn off the alarm, I had to use the keypad on the door to get it to unlock and turn off the alarm. The power seat and door chime will come on whenever I turn off the truck and even with the key out of the ignition it continues to chime until I shut the door, all the while my MM is booting up as if I turned on the ignition. Should I take the truck to stock, reset the MM and then load it fresh? Anyone experience this problem or something like it?

 

[bigrpowr]

probably a ground or connection issue somewhere. P0000 is nothing, it just means there has been a code in the past .

 

[doo dah]

I have LED reverse lights in the rear bumper and when I turned the ignition on to reset the MM they flash on and off and I can hear a sound like a flasher. I have 2 LED lightbars on the front, one works fine and one is weak or not working at all. When I turn the lightbar on the rear lights stop flashing but are still on. If I press the brake pedal the reverse light stay on and stop flashing, when I let off the pedal they go back to flashing. truck starts and runs fine. Still won't shut off with the lights on, if I turn off the truck and take the key out it still runs until I turn off the light switch, the truck shuts down when I turn the lights off. I have not wired anything on the truck in over 2 years so I have no idea where to start looking for a ground issue. No chance of a bad headlight switch, bad PCM/ECM etc...? Maybe a battery is bad, still enough to start the truck but maybe low voltage is causing issues?

 

[78f100]

I would test the batteries first. Low voltage makes crazy things happen.

 

[JRLott]

I would test the batteries first. Low voltage makes crazy things happen.

If the batteries are the issue, this is the strangest set of problems I've read about.

I believe an exorcism is in order involving five gallons of gas, some dynamite, and a cliff. :biggun:

 

[gnxtc2]

Check the big electrical harness connector above the E-brake?

Billy T.
[email protected]

 

[06-sixoh]

I agree with the batteries. If you have the original batteries, it's getting about time to invest in a set anyways. These trucks take a lot of voltage to run and start.

I would chase a bad ground next. Check all the grounds you can think of.

 

[doo dah]

Batteries are less than a year old but I will still get them checked. I am going to remove the left headlight and see what that does then I guess I'll look at the trailer plug since this all started after I hooked up the flatbed. It has been raining here since Friday morning non stop so I have to run out when it lets up a little then get what I can done before I am soaked. Oh, one more thing when I was pulling the trailer and would use the left turn signal the trailer brakes pulsed with the blinker..............

 

[doo dah]

If the batteries are the issue, this is the strangest set of problems I've read about.

I believe an exorcism is in order involving five gallons of gas, some dynamite, and a cliff. :biggun:

I don't want to throw it off a cliff but certainly the strangest stuff I have ever experienced. I can't seem to locate a root cause because everything is so random. I would say lights but then why don't the wipers work? No telling what else is jacked up that I haven't come across riest:

 

[JRLott]

Strange it certainly is. Interested to see the resolution. Hope you get it figured out soon. Keep us posted.

 

[doo dah]

Drove to AutoZone since I bought the batteries there and they had 15 people in line with one employee in the store. Waited for 30 minutes and line never moved so I left. When I got in the truck I noticed driver seat moved back as normal when I opened the door, no door chime, MM was not coming on, etc...so I started the truck and both headlights worked, no reverse light flashing, lightbars worked, etc...so I thought WTF but ok as long as it is good. Drove home and went through routine to make sure and everything back to the way it was before, runs with ignition off and no key, reverse lights flashing, one light bar works other doesn't, right side headlight/marker light work left does not............now I'm really dumbfounded. Will try AZ again later today when the crowd is gone.

 

[Jomax]

I bet it's your batteries


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[gnxtc2]

Did you check the harness by the E-brake? There is a connector there that get loose and causes the issues you're reporting.

Billy T.
[email protected]

 

[doo dah]

Batteries are normal. Looks like I'll be taking it to the dealer, maybe they can pinpoint it right away with the scanner.

 

[doo dah]

Did you check the harness by the E-brake? There is a connector there that get loose and causes the issues you're reporting.

Billy T.
[email protected]

Yep, all tight.

 

[Profuzz]

Did you load test each battery? Disconnected from truck


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[JRLott]

I had an 84 GMC 3/4 ton 350 granny low 4 speed that I alternated changing the battery and alternator every month until the parts store guy sugggested an interstate battery. Naturally, he wasn't supposed to give me credit for the POS $30 battery purchased there I'd been swapping. He did anyway and I paid the $70 difference. That sucked for a 16 yo kid, but I didn't replace another battery or alternator in that truck. I've been a firm believer in them since and every battery I've had to replace has said Interstate on it for dang near 30 years now.

 

[CATDiezel]

Battery testing is rather simple. If they load test then so be it. Anything above 12.6v is considered good.

This sounds like a noise issue from either a failed light or diode causing meniscus return voltage and one of the modules is detecting it as a signal input.

Please disconnect all accessory lights and start from there. Anything lighting not stock.

A certain frequency from any transformer on one of the light bars. Or even LED lights could easily cause this. Ever powered up a very high frequency and watted radio near sensitive equipment. It's the same ordeal. It's noise generated on a communications path and it causes the silicone chip to loose it's mind.

The same can also be from an accessory with a transformer without a shielded ground to carry or direct noise away.

If a power wire is "dirty" or u shielded and also sitting next to mod bus or can comms it can inherently put generated false signal on the line.

Anything with a transforming generator should have a diode sized properly to stop these issues. In the case of light bars it should be a zener diode if a regular diode proves insufficient. Either that or a isolated clean 24v power supply along with a shield ground. (Terminate the shield on one end only or your simply adding a ground that is not capable of carrying stray noise and loose voltage)

I could be wrong but you don't have either a battery or connection problem.

You have a module that is unhappy. Just try unplugging all aftermarket lighting first and see. However if a light caused this issue it is highly possible to fry the new module. Remember it's just a delicate silicone chip and the wrong frequency can nuke it... although it's protected by a series of diodes and resistors. It happens all the time. Especially if the noise is incoming and not outgoing.

 

[doo dah]

Batteries were @ 12.75v and 100% charged, both checked out the same. I disconnected the left LED headlight bulb and no change. Light bars are wired through the upfitter switches on a common chassis ground, I didn't disconnect them but can try tomorrow. Still raining in buckets here so not much opportunity to get out and do everything but feel like I have done what I can other than disconnecting the trailer plug to see if something got fried there when I hooked up the trailer yesterday. Taking it to the dealer tomorrow.

 

[CATDiezel]

Keep us updated.

You have a interesting problem.