Electrical gremlin...

[MedicPathetic]

Hey guys, I'm hoping that you all can give me some pointers on where to start looking. I have an electrical issue that has gotten worse. The lamp out light comes on and off. The headlights come on by themselves when the truck is running. Today, I took the truck for an alignment and it was running fine, I pick it up and the truck has no power at lower RPM, sluggish on the low end, but when I get to about 2000 rpm it seems back to normal...I had to limp it home. The outside air temp sensor said that it was like 24 degrees outside when it was, in fact, about 85 degrees, then went back to reading the correct temp. I just checked it again, and I have no wipers, no turn signals, no bright lights, headlights on with the switch off...The lamp out chime and light seems to happen when I hit a bump

Before this, I had an issue with the wipers coming on when I key on the truck but I found that some rats had eaten the wires around the motor, so I suspect something similar has happened elsewhere. While troubleshooting the wiper issue I put a new FCM in the truck and pulled the TIPM apart and inspected that with no issues found. Truck has new battery cables and batteries as well.

And the issue is intermittent too...so those are always fun.

The truck scans codes for P2121 accelerator pedal position, P2509 intermittent power input signal to the Powertrain Control Module (PCM), and P0514 malfunction battery temperature sensor.

Does anyone have any ideas where I should start looking for chewed-up wiring? I'm assuming the engine harness would be the only thing to cause this, or could something on the body harness also cause it too? At this point i'm saying that the truck is possessed.

 

[MedicPathetic]

I guess my main question is, does the headlights, accelerator pedal sensor, and turn signals all connect to the TIPM on the same connector?

 

[bighammer]

I would start with the power distribution center. There's a big connector on the bottom side of it that can get screwed up. (especially if you power wash your engine compartment) Disconnect the negatives on your battery and pull it out. My '03 is halfway cut up and parted out, but I'm pretty sure that part is still there, so if you need one, it's yours for the postage. (no clue of its condition, but it worked when I quit driving it a few years ago)

 

[bigceltic]

P2509 intermittent power input signal to the Powertrain Control Module (PCM), and P0514 malfunction battery temperature sensor.

I was getting intermittent P2509 code and my final fix was to replace all the battery cables - I had tried cleaning all the grounds and terminals but could not get it to go away - replacing the cables, esp the crossover cable, fixed my issue.

 

[Ozymandias]

Sound very much like a ground issue, to many systems at the same time start to fail.

Take out your Mulitmeter and start measuring differentials from end to end. I'm sure you'll find voltage drops along the way.
Don't forget, electricity is a circuit, it needs to be perfect from pole to pole. To many people focus on the positiv side and overlooking grounds.

 

[petersonj]

To many people focus on the positiv side and overlooking grounds.

It just goes to show that although a positive attitude is always recommended, a negative attitude is important, too.

An attempt at humor.

- John

 

[Yo Hoot]

Having similar issues. Found some great videos on the most likely cause. Either the Fuse box (power distribution center) or the FPM mounted on the side of the fusebox.
I found a guy on another forum that happened to have brand new fuse box and a remanufactured FCM so I have them in hand. When I get time I'll do the diagnosis shown in these videos.

 

[MedicPathetic]

Thanks for all the help you guys! I think I've figured it out. C1 connector (the blue one) on the TIPM is a little loose and the headlight issues go away and things start working when I reseat it. I ordered a rebuilt connector from Maks and will replace it. I don't have a diagram to see if the APP sensor goes through that connector but i'm hoping that it does and that is not a seperate issue. Again, thanks for all the help guys, especially Bighammer! Also if anyone else finds this later on looking for answers, https://tipmrebuilders.com/ has a lot of resources also that are helpful too.

 

[MedicPathetic]

Also, this was helpful too, I just wish that I knew what all the B+ leads coming off were powering:

https://hf-files-oregon.s3.amazonaw...790efca58e/5026032_TIPM_Plugs_and_Pinouts.pdf

 

[Yo Hoot]

Thanks for all the help you guys! I think I've figured it out. C1 connector (the blue one) on the TIPM is a little loose and the headlight issues go away and things start working when I reseat it. I ordered a rebuilt connector from Maks and will replace it. I don't have a diagram to see if the APP sensor goes through that connector but i'm hoping that it does and that is not a seperate issue. Again, thanks for all the help guys, especially Bighammer! Also if anyone else finds this later on looking for answers, https://tipmrebuilders.com/ has a lot of resources also that are helpful too.

Well now, I'll have to have a look at my connectors. Thank you.

 

[Ozymandias]

How can this connector be loose? It is a latching design.

 

[Yo Hoot]

How can this connector be loose? It is a latching design.

It may be the internal board is corroded and wiggling it gets it to reconnect. The second video I posted the guy tore the fuse box apart and found a corroded trace..

 

[MedicPathetic]

How can this connector be loose? It is a latching design.

It's not latching. Upon further inspection, it appears that the latch got brittle and gave up after 20 years. Which now makes me question the rest of them....but that's a who lot of de-pinning and re-pinning to do to change them all.

 

[Ozymandias]

Uh that is evil if they just start to fall apart from old age, good to know.