QuestionQUESTION: I have a 2007 chrysler t&c. The front & rear running/drive lights
don't work. I tested the 2 15 amp fuses and am not getting power to them. The fuses tested ok. I reverse wired, like jumper wires, 2 wires from the + batt terminal and then touched the tips of the fuses with the other end of the wires. The lights came on.
From what I've been reading on other websites, they've stated bad switches, ground wires, and other issues that I wasn't comprehending.
ANSWER: Hi Rusty,
I just found your question in the "pool" to which it had been referred by Kevin after a one week delay.
Have you solved this problem? If not, what are numbers of the fuses that are not getting power to them just to be sure I understand what you have found? And you have no headlamps or tail lamps? Any other exterior front or rear lamps that are working/are not working?
The circuitry involves the body control module which takes its cues from the ignition switch, and the integrated power module/front control module which takes ita cues from the body control module.
I would start with the headlamp switch to test whether it shows a change in the voltage output when you move it for off to on. The switch is actually a series of resistors which modify the voltage signal sent to the body control module and it may be that the on position contact is faulty. Do the other positions of that switch seem to work?
Have you done any other testing?
I have the '06 and '08 wiring diagrams so I will need to verify those are identical and if so then the '07 should be the same. Let me know where things stand and we'll go from there.
Sorry for the delay.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland,
The problem has been taken care of for now.
I went to a local Auto Electrical repair shop here in town.
I told him what the problem was and he knew what it was. You were saying the
same thing that he said about the modules controling the lights.
He also showed me something else. There is a 20 amp fuse that controls the
computer in the car. He pulled the fuse out, waited around 5 seconds, put it back in and the lights worked.
He said this could be a temp fix, but for how long was in doubt.
Next he told me that to replace the front control module would be very expensive
and that he would do it himself but he was told that he couldn't purchase
the computer software needed to program the module.
Now I don't know but it sounds like chrysler is trying to keep the softwere
in house to discourage compitition. My2c.
So, for now I will keep pulling the fuse until I decide whether or not to make a permenant repair.if it becomes necessary.
I'd like your feedback on this.
Thank you for all your help.
Rusty
AnswerHi Rusty,
That is very useful information about restoring control of the headlamp switch. It no doubt could also apply to other similar 'glitches' with things related to the body control and front control modules.
The front control module is a 'black box' as far as internal wiring details are concerned.
I looked at the wiring and suspect that the fuse he pulled is #17, correct? Or was it fuse #14 which is also 20 amp and powers the body control module?
Fuse #17 is the only 20 amp fuse that powers the ecm/pcm directly from the battery at all times, and similarly #14 for the body control module.
It is not clear to me why pulling a fuse for 5 seconds would correct a problem but it is good to know that it worked for your headlight problem. I'll suggest that technique to other minivan owners who ask about similar isolated issues involving circuits that route through the bcm and fcm and are driven by a variable voltage-divider type of switch.
But do let me know which fuse it is.
Thank you for sharing that information.
Roland
