2004 Ram Headlamp Out Light

[HBarlow]

An old friend of mine called just before lunch from Pahrump to ask for TDR assistance in diagnosing and correcting a headlamp out problem on his 2004 Ram 2500. He is a TDR member and attended May Madness every year but is not very computer savvy and doesn't post.

He has been an RV transporter for more than ten years and his current Ram probably has 400,000 miles on the odometer.

His truck recently displayed a "lamp out" light in the instrument panel and the left low beam headlamp doesn't work. He purchased and installed a new lamp which didn't correct the problem. He then removed the new lamp and tried it on the right side and the lamp lighted. The bulb is good.

Has anyone experienced a similar problem?

Is there an electronic control module in the circuit between dash light switch and lamp?

All information and advice will be appreciated.

 

[jelag]

Harvey... .

I had the daytime running lights turned on, and I used to use the bright box from Geno's... .

It caused the FCM (forward control module) as I remember to go south and gave me fits... Once I took off the bright box things went back to normal... I'd prefer the daytime lights to both beams at night.....

I might have the module's name incorrect... . but there is a module that controls this...

We've seen bad connections on the tail lamps, and turn signals turn this light on as well... and usually cleaning the connectors and putting in some dielectric grease would turn off the light when the bulb was good... .

Hope this helps...

 

[HBarlow]

Thanks, Jim, I'll pass that suggestion back to my old friend.

If anyone else has other thoughts throw them out here as well.

 

[scootergmc]

What he said...


Here's the thread that came to mind when I read your post:

https://www.turbodieselregister.com...discussions/198790-lastest-headlight-out.html

 

[jhenderson]

The FCM mounts behind the fuse box, next to the fender. It plugs into the fuse box and is held in with 4 screws. Remove the FCM, clean all connections, and ever so slightly twist the flat pin connectors to insure a good connection before you invest in a new one. If this does not fix the problem check online for the best price,most likely about 40% less than the dealer.

 

[HBarlow]

Thanks guys. That's excellent, complete, detailed information.

You can't beat the TDR for solutions to problems!

 

[HBarlow]

UPDATE: My friend called today to report that he took his truck to his local dealer and had the FCM replaced and the problem was solved. I'm not clear why he didn't simply buy the module and replace it himself. The dealer convinced him that reprogramming was required and charged him a large labor charge. I am skeptical about the need for that but don't know, maybe it was required.

Anyway, he thanked me and the TDR members who provided the answers.

 

[Kilroy]

I know this is an old thread, but still important for me.



I've had the right headlight out on my truck for the last 18 months, both for a while. After reading as many threads as I could (I hadn't seen this one though) , I deduced that it shouldn't take a new PCM to fix problem. I've tried many different things, none of which have worked for long. But I still don't think a PCM is necessary. Whats been done:



Took off PCM, squirted contact cleaner on contacts, bent them slightly (but not twisted as in quote, will try this later) put back together with dialectic grease and had both lights working. Hurray.



Was also having an issue with the battery dying while sitting. After reading more threads, decided to take out fuse box, take apart and look for corrosion. Didn't find any. Put back together, right headlight was now out again.



Took PCM off again, cleaned contracts using emery paper. Put together. Headlight worked again, for about 3 days before it went off.



Had read and been told that should check and clean grounds on truck. Hadn't done so. But after a muddy trip in the MI UP I was cleaning the truck and engine with pressure washer (carefully), just for kicks I thought I would check lights. They both worked. Right one went out again after everything dried.



Deduced this is a ground problem, so found two grounds on passenger side fender and took off and cleaned. Headlight worked again, for about a week.



Recently drove in a lot of rain, noticed headlight came on again, only to go off when everything dried up.



Found two more grounds on driver side fender. Cleaning didn't make any difference.



Any suggestions where to look for this bad connection(s)?



Thanks

The FCM mounts behind the fuse box, next to the fender. It plugs into the fuse box and is held in with 4 screws. Remove the FCM, clean all connections, and ever so slightly twist the flat pin connectors to insure a good connection before you invest in a new one. If this does not fix the problem check online for the best price,most likely about 40% less than the dealer.

 

[BigPapa]

It's not the PCM, it's the electronic unit under the fuse panel that's under the hood.



Also, the "programming" consists of installing the unit and then leaving the ignition switch in the run position for 30 minutes.



Scott

 

[jhenderson]

Re- read my post 5 entries back.

 

[BigPapa]

No need to, he quoted it right there in his thread. He continues to refer to the PCM, not the FCM.



The comment on "programming" was intended to keep someone else from paying labor for turning the switch on.



Scott

 

[Kilroy]

Sorry about the confusion with PCM and FCM. Getting old. My new excuse, now that I can get SS, and I'm sticking to it.



I've had the box off a couple of times now to clean the connectors coming into the bottom of the panel/box and didn't take notice of another electronic thing.



Not sure what your referring to under the fuse panel (box?).

It's not the PCM, it's the electronic unit under the fuse panel that's under the hood.



Also, the "programming" consists of installing the unit and then leaving the ignition switch in the run position for 30 minutes.



Scott

 

[jhenderson]

The FCM is attached to the fender side of the fuse box with 4 fasteners. Remove the fasteners and pull the FCM straight out. You will see the pin connections that need to be cleaned and tweaked.