Went off roading last weekend with my ram and after washing it all down I am having a major electrical issue with it.


All the exterior lights will come on and go off all on their own.
Truck will stay running for a while even after turning the key off
Overhead console reads 130 F outside (its 25 right now)
Turn Signals blink stupid fast.




Been reading about the fuse box and FCM being bad in these trucks, could this be my issue?



Also whats strange is for the longest time my trailer brakes wouldnt work on this truck unless it raining or there was water on the ground. Now they work with all this acting up. Could this be part of a bad fuse box and FCM ?

 

Sounds like you have the fuse box corrosion issue. Look on the underside of your fuse box in the engine compartment. It plagues the 02-05's as it's open to the elements.

 

You are right, PDM took a dump on me, I tried to clean it as what I found on the web, and it helped stop the lights coming on all on their own, but now the truck is dead in the water as far as running.



Just my luck that 02 is its own year and the rest are different, just how life goes for me right now!!

 

I'm sorry to hear in regards to being an '02, but atleast you found your problem!

I would warn you about buying used for fear of having the same issue, so be skeptical and critical in your purchase!

You might want to even see if you can buy an OEM one even if it's like $600.

 

If you have the 5.9 it may be different, I know the 02 4.7 has the same pdc as an 03-05 regardless of engines.

 

According to the stealership it is different, could be my truck though since there are hardly any I've found like it, mainly due to the adjustable foot pedals and the side curtain air bags.

 

Hate to bring this back up to the top, but now I have yet another glitch .

My drivers side tail light running lights and license plate light are not working. The pass side works just fine, but the drivers side doesn't.


I have : turn signals, brake lamp, and reverse lamp. But the running lights aren't working?



Could this be the fcm ??? Maybe the wiring harness to the tail light?? Bad part is the lamp out system indicates all is well....

 

I don't believe that the license plate lights are monitored by the 'lamp out' system, but obviously we know the tails and runnings lights are. I would pull a different bulb out, or just disconnect a headlight plug and see if the 'lamp out' system is working at all. If the lamp out works for the light you just pulled out, I would think the problem to be bigger than the wiring harness to the tail light. Do you have access to the service manual, can you verify that the circuit works correctly on the bottom of the fuse box?

 

Swap the tail light assemblies on left an right side, if he problem moves to the right it's corroded rail inside the lamp. Cheap part the bulb carrier assy.

 

Well after spending time tracking things back I figured it out. For some damn reason the running light circuit also runs through trailer light circuit. The fuse was blown in the trailer light circuit and that killed the running light circuit (which has a different fuse to begin with!!!!)


Now to fix my seat heaters and seat track.....