13 Button OBC Resetting

[4tDX]

I have a 13 button OBC on a '87 325i that resets while driving. When it resets the back light stays on, but the screen is blank and will remain in this state for varying amount of time before having a complete reset - meaning when i can once again interact with the OBC and reset the clock and units. It only resets while driving which leads me to believe it is a lose connection, but not necessarily a power loss. Everything else is the car is working properly, radio, instrument cluster, check panel, etc.



Things I've done so far:

• Cleaned battery terminals
• Cleaned grounding connections,
• Check fuses
• Check electrical connectors
• Was not able to cause a reset when starting the car or increasing the power draw

I have yet to look inside the OBC itself, but before I do that is there any thing else I should check first?
Has anyone else had a similar problem and solution?
Are there common failure points on the OBC PCBs?

[george graves]

IIRC, the circuit for the back light is on it's own wire going into the OBC. So it shutting down might be the power to it. I could be wrong on that, but that's what I recall. So, what I would start with is reseating the OBC plug, and the cluster plugs( a dozen times to be sure). These are 30 year old cars, and the electronics are starting to become an issue. It's not uncommon for an OBC to go haywire too - so there's that.

FYI, you can also use some contact cleaner. Deoxit is the go to in the electronics world. Others use Kontakt 61 - but harder to find.