Hi,
Can anyone help me with diagnosing my park light problem?

I have checked the continuity of all the front and rear bulbs, along with the license plate. This includes the front heads and fogs and the turns, which all work 100% .
However, when I turn on the lighting multi-function switch to the first position, no park lights front or rear. They used to be 100% OK.
This is with and without the ignition on, the park brake on/off etc.
I have checked all the fuses in the top of the power distribution center (fuse box) and all apear ok.
I have swopped out the Park relay in position #73 with the relay in position #70 as they have the same id numbers on them and the same circuit diagram on the side showing how they are internally connected.
Still no park lights. I also checked the relay out using the trouble shooting guide in the service manual and all the continuity and resistance readings are fine. I also connected a batterry up to the appropriate relay contacts, and you could here and feel the coil pulling in the contct, also the continuity went from open to short as expected during this test. So the park lamp relay is OK.
There appears to be no 12v feed to the lamps, front or rear when switching the headlamp switch to the park position.
I'm now RAPIDLY running out of ideas?
Anyone know of any hidden fuses I might have overlooked etc?

I hope it isn't the FCM/front control module. I don't know how on earth to test that and I have no access to a OBD111 reader over here in the UK.

No "lamp out" error is reported on the instrument dash cluster either. Also, there is no error codes in the oddometer display when the 3 X ignition on/off trick is done

Any and all ideas to solve this are very much appreciated.
Please look at my sig to see year and type of truck etc.
Cheers,
Al.
P.S. Can anyone get an estimate for an FCM module for an 03 Hemi, just in case I need to get one please?
Al.

 

An amendment to my post :-


Can you use a Superchips programmer to read the diagnostic codes and trouble shoot like the Chrysler DRB111 tool ?
Al.

 

that should work i believe that superchips does that

 

Hey Al,
This may sound crazy, but have you checked to see if your chasis ground is ok?

 

Al,

I was looking at the FSM for the parking lights. If you pull the relay, make up a jumper from male spade terminals I would guess. If you jump terminals 30 and 87, the park lamps should come on, if not there is a down line fuse also, 10amp.

This is in section 8, page 1651

 

Hi Gone Fishin,
Tried the jumper from the normally live terminal 30 to normally open pin 87 on the park lamp relay.
All the park and license plate lights came on fine.
This, I guess, proves that everything south of the relay, so to speak out to the lights including the fuses is OK.
What we have done by jumpering the relay is cut out of the electrical loop the FCM. Am I correct?
What I have noticed is that even though the Park lights etc don't come on, if you have the door open, the warning chime telling you the lights are on kicks in. So some part of the FCM must be working to read that the headlamp control switch is in the on/park lights position..............

I'm just about to remove the FCM module and clean and check the connections, then reseat and reinstall it.
I'll post to let you know what I've found.
Where is the chassis ground your talking about?
Would this contribute to the FCM not working even though the lights do when jumpered?
Cheers btw for the help mate.[sm=deal.gif]
Al.

 

Gone Fishin

Just sorted out my problem.
I removed the FCM and it was a little peppered, with a coating of light dust and mud.
Also, all the connectors underneath the PDC (power distribution center) were covered with the same.
I removed all the connectors and the FCM, spraying and pulling on and off the connectors, several times, to alow the WD40 to clean the contacts etc.
All now apears fine.
I'll have to keep an eye on it, but so far everythings OK.
I guess either a loose or intermittent connection or indeed a connection of high resistance causing the FCM to fail, might have been the problem.
Either way I'm very happy and whats more, I've learned a lot about my our trucks and that in itself is invaluable.
Thanks for the replys to my postings and for the positive encouragement.
This site and the people on here ROCK !!!!!!!
Warm regards from a very sunny (makes a change) and hot England.
All the best.
Al.
[sm=deal.gif]

 

Al,

Just as a follow-up to your problem. We all know how touchy these things are these days to electrical misfortunes. Connectors are often the culprit, because they eventually let some moisture in and start a slow oxidizing process, higher resistance. These computers are sensitive to this and recognize it. What you might want to consider doing is pulling apart those "peppered" connections, cleaning them good with an electrical cleaner spray, then putting a small dab of silicone grease in the connection, and putting it back together. This does two things, it helps stop the breakdown of the connector material, and intergral seal, and it coats the conductors and stops the oxidation. Just dont get crazy with it. Now let me emphasize, SILICONE GREASE, not RTV or silicone sealant that hardens up. The grease will always be semi fluid. Also, make sure the electrical cleaner is completely dry before applying the grease
and reconnecting.

Happy Truckin' glad I could help

 

Sounds like a plan.

I'll finish up with the Silicone grease so I stay out of trouble.
Once again, thanks and cheers for the help bud.
Al.

 

Have to resurrect this one Al. Same boat as you, and most of us. I have the PDC out right now and have the FCM pulled off of that. Did you guys pull the PDC apart, and if so how in world did you do that?

Thanks