dodge grand caravan 1996 the cluster gauges

[labmik]

Need help please

The gauges in the car ( temp, rpm, speed, and gas “ do not works . some times came on for a short period then go
When the gauges go dead the internal light switch and the front wipers do not work as normal .
Some suggested to replace the BCM IN THE CAR.
But before doing that I am told by my mechanic that the BCM have nothing to do with the CLUSTER and it is only to control the engine performance.
Have tried to solder the cluster ,even replaces it with another one but did not solve the problem

Any advise , help - please

[RIP]

I'll be generous and say your mechanic is getting the BCM confused with the PCM (engine computer). In any case, might be time to find another mechanic. The BCM has everything to do with controling the instrument cluster.

There are few electical circuits in the van that aren't effected by the Body Control Computer (BCM). Other than the start circuit, it won't effect engine performance. Key to your problem, the BCM is a primary component in the Chrysler Collision Detection (CCD) multyplex data bus. This data bus consists of a set of wires and microprocessors all the computers/modules use to communicate with each other. High resistance anywhere in the bus will create seemingly unassociated problems. Failures usually happen at the instrument cluster solder connections, the BCM, or the climate control panel connection. You've eliminated the cluster, now you need to check the climate control panel connection. Many times the connector overheats and melts opening the data bus circuit and disabling the instrument panel. If you don't see a problem there, the BCM becomes the target.

EDIT Here's more on the subject plus pictures: http://forum.chryslerminivan.net/showthread.php?t=6547 More pics on page 2.

[labmik]

thanks for the reply.
the bcm is the computer under the fuse box ??
the auto junk yard sales man asked me for the number of the Bcm
is this number important or any bcm for dodge grand caravan 1996 3.3L WILL DO THE JOB
I FOUND A NUMBER 6607 written on the bcm . is this the number

[RIP]

The BCM is on the back of the junction block (interior fuse panel). The part number is very important if you want all the accessories to work correctly. A single model year can have several different BCMs. I want to say the number you found is too short. I think it has something on the order of 10 digits. Not sure.

Two more things to keep in mind:
> You'll have to go to the dealer and have the software updated so the vans mileage display will match what's actually on the van. Say if you have 100k miles on your van and the van you take the BCM from has 200K miles, 200K miles will be displayed on your odometer.
> It's important the van the BCM came from has the same security system configuration as your van. If it's different the Powertrain Control Module (engine computer) could be damaged.

On the whole, if you really want to go with a BCM before checking the climate control panel connection, I'd recommend looking on the internet. Those companies are generally more aware of BCM specifics.