So, the BCM is dead?

1997, Dodge Intrepid. 130K miles.

The currently situations are: (just in case you want to see it yourself, I made a short video of the problem, see here:

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1) The car can start and drive, although if I put it to P, the sound from the engine seems to indicate that the engine sometimes goes faster sometimes goes slower.

2) The wiper will start to work at the same time the car is powered on, and will not stop.

3) The engine speed meter and the car speed meter give random readings. The engine temperature meter has no reading. The gas meter has no reading (sometimes will have some reading).

4) Turning signals seem not work too.

5) The light inside the car is not working (usually when I open the car door, it should light up and dim slowly).

6) The power door lock does not work.

I have done the following checks:

1) I have taken off and checked the multi function switch (the one for the turning lights, etc) and the headlights switch, they seem OK according to the manual. And if I start the car without the above two switches, all the problems still there.

2) I have confirmed that the terminals of the battery are clean and the cables to them are good. Also, the negative terminal is connected to the car's frame properly (as suggested by a friend).

3) All the fuses are OK.

So, I think the BCM is dead. How is your guys' idea?

By the way, if I take out the BCM, how can I tell whether it is OK or not? (for example, by using a multi meter, etc)

Thanks a lot. :-)

Well, you certainly have some electrical gremlins, and they could be related to the BCM. This is going to be a tricky one for a DIYer to diagnose properly, although I believe its possible if you ask yourself the right questions and proceed methodically. It would be extremely helpful to have a copy of the factory service manual and body diagnostics manual as well.

One common thing to check before condemning the BCM are its ground connections. You may also have one or more electrical shorts in the wiring harness causing issues such as this.

Did all of these symptoms come on suddenly? Was the car involved in any flooding, an accident, or anything else unusual? Is the battery at full strength? Was the car jumpstarted any time recently? Was there any work done on the charging system? Has there been any work done on the car at all recently?

It's interesting, I think, that the problem manifests itself when the engine is running. How about if you just switch the key to the 'run' position without starting it? Same things?

Will the car display its dashboard flash codes using the key-on-key-off-key-on-key-off-key-on procedure? (Google this newsgroup if you need more description)

--Geoff