I've got a 2004 Dodge Diesel 2500 Ram & recently I had low beam go out on my driver side headlight. Certainly this can't be too hard to fix...just replace the headlight. WRONG! Replacing the headlight did not fix the problem.

I took a digital voltmeter & ck'd the bulb socket on hi & lo beam & I had voltage but still the headlight only worked on hi-beam & I continued to get an warning message on the dash. Even though I do have voltage, the fuse block/front control module (FCM) is not allowing any power to flow thru to the headlamp on the lo-setting.

I guess the next step is to 1) lift negative battery leads & 2) pull the fuse block to exam for corrosion & 3) pull connectors from the FCM & 4) replug to see if I can revive the system.

Any suggestions?

 

did you check for a ground? if you said you checked for power on both the hi and low beam and had power... then the fuse block/ front control module is letting power through to the headlamp on the low setting.
Check for a ground and then go from there.. you could always make a jumper and see if your light bulb iluminates too

 

Just to clarify....although I measured voltage at the socket on Hi & LO beam settings, I'm sure my digital voltmeter which its high impedance input is not putting enough load on the circuit. Since the headlight does not work on low beam & I've switched bulbs & I have lamp warning on my dash, I'm betting that the FCM is limiting current to the headlight for some reason. A low impedance voltmeter (a cheap analog meter) would have been more telling. Well, today I'm going to pull the fuse block/FCM assembly & do some tweaking, twisting, flexing, etc. & see if I bring about any changes. I guess I could open up the FCM (with a can opener?) and see if any components have "leaked out their smoke."

 

when u check voltage with a multimeter your not putting a load on the circuit? thats when you check continuity..... do a contuniuty check from the ground wire to a body ground..

 

k5avj,
Did you ever figure out what was causing your problem? My truck is doing the exact same thing now. Thanks!

-Dean

 

From all of the threads I have read, it is almost always the PDC that is the issue. I know a few guys who have had to replace the entire PDC to get thier lights back working.

 

I lifted the negative leads from the batteries & then pulled the fuse block (power distr center) and unplugged the front control module(FCM) and then reconnected everything & the alarm went away the lo-beam headlight worked again.....for about 4 weeks. Now, the problem has reappeared. I'm going to order a replacement FCM & see if that fixes the problem

 

I have a 2004 Dodge 1500 Hemi, and I had the same problem with the drivers side low beam not working, but both Hi-beams worked just fine.

Took it to the dealer and paid to have him trouble shoot it....after $95.00, he said the PDC was bad, and it woud be about $500.00 to order a new one and install it.

Woah....nellie....

I went to the wrecking yard, got a PDC with the computer module for $175.00, and installed it....Voila....problem fixed.

BTW, I was asked by the dealer if I had "Washed" my Engine....yep, sure did....and it did start doing this, right after that....hmmmmmm

 

What's the PDC?

My truck has the same issue. I know of the fcm but just saw this thread about the PDC.

Thanks in advance.

 

Power Distribution Control AKA Fuse Box