BCM going bad

[rpetry]

Hi!

 

I have a 1988 Reatta, the CRT screen is crazy.  It remains dark most of the time but every once in a while it comes up and works for a few minutes, lets me adjust the air controls and then the screen freezes.  Today it came up and did the same thing and then displayed a warning screen that there was an electrical problem that needed to be serviced.  It froze there until I turned the ignition off and opened the door.  I pulled all the connectors off the back of the CRT screen and cleaned them with electronics cleaner and reseated them.  I did the same with the BCM connectors.  The screen is a waking up a bit more since then but the dash also displays an electrical problem.  I can't ever get to the codes on the CRT screen in time to get them. I am becoming convinced this is a BCM issue going on.  Also the IPC has shown an error from time to time where the odometer is and when it does this, the trip meter resets.  Am i on the right path?

[Ronnie]

I think you are on the right track but there is a few tests you can do... The next time it happens, get the car into a dark space, or cover the photocell on the dash really good so the BCM thinks it is dark outside. Then move the dimmer slider on the headlight switch back and forth and see if the lights on the IPC and CRT dim and brighten as they should when you  move the slider. Then move the slider all the way to the right and see if the interior lights come on. The BCM actually controls all of that. That will at least tell you if the BCM is awake and operating.

[rpetry]

Thanks!  They do work correctly and I replaced the photocell with the how to instructions on this site.  The dash buttons (light switches, wiper switches and shifter panel) would not light up at night no matter what, and this corrected that issue.  The slider also dims my IPC at night as it should. 

 

I have a replacement BCM on the way, I will try it out tomorrow when it arrives.  I also read there are ground splices underneath the passenger's seat that might need to be recrimped/soldered?  I'm thinking it is either something in the CRT unit or the BCM, possibly both, but since the IPC does error out occasionally I am thinking the BCM has a problem.