QuestionQUESTION: Hello Mr. Finston, I have a 2000 Chrysler Town & Country, that all of a sudden lost the dash lights and the running lights. Headlights, brakelights, turn signals all work. No voltage at the under dash fuse box #1 10amp for dash lights or either the left or right park lamp 15amp fuses. If I introduce voltage at either of these fuses, the running lights and dash lights work. I'm thinking BCM is bad. What do you think?
ANSWER: Hi Roy,
I'm working with the '98 diagrams which are identical or similar to the '00. The parking lamp relay has to be closed to get power to fuses 1,3,5 to power up the running lights and also to send the 'message' to the body computer to turn on the dash lights. The body computer does get a 'que' from the headlamp switch to close the parking lamp relay. So see if that relay clicks or not. It might be the headlamp switch, but that circuit would probably, if faulty, not turn on the headlamps either. If the park lamp relay clicks, then fuse 22 (40 Amp) in the power box under the hood is blown and not delivering current to the contacts inside the relay or the contacts are oxidized; if not, then the relay may be faulty (switch it out to see if that is so). It is the rearmost big relay on the outboard side of the power distribution box in the engine compartment.
I doubt it is the body computer itself at fault.
Roland
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QUESTION: Mr Finston,I've checked the 40amp fuses under the hood in the power distribution box they have current. The relay is not clicking. I have opened it up(removed top cover of relay), if I close the contact, the park lights come on. there are 4 terminals on the relay numbered 85,86,87,30. If I send power to terminal 87 the lights come on.In looking at a schematic, the BCM has a park lamp relay controller within it but I'm not sure which way the current flows.
AnswerHi Roy,
Do you have 12V on pins 30 and 86 that should be there coming from fuse 22? If you do, then the body control module is either not grounding pin 85 to close the relay or the relay coil is 'open' and not responding to the grounding. The wire that carries the grounding is pink/dark blue and goes from the relay socket's pin 85 to pin 9 of the upper right corner 38-pin plug at the fuse box under the dash, so check that wire for continuity. If it is OK then the body controller is not sensing the request from the headlamp switch to close the relay in the park and in the headlamp positions.
If you don't have running lights in both the park and the headlamp position of the switch, but you do have headlamps, then I would wonder if there is an issue with body controller.
You might try getting a fault code readout of the body computer to see if it recognized a fault that would explain the situation. That is best done with a good quality code reader that can inquire of the body controller memory. The ignition key can be used to get codes, but I am not certain it can access the body computer or just the engine computer. Turn the key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then see if the odometer's mileage reading changes to show any 4-digit numbers with either P (engine/tranmission) of B (body) prefixes which would be codes. Let me know.
Roland
PS Sorry for the delay but my internet connection is flakey. If you would be so kind as to rate/nominate me that would be appreciated.
