General Tech Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.

1991 Deville ... Instrument Cluster +

Old 01-10-2019, 08:18 PM
Junior Member
Thread Starter
Join Date: Jan 2019
Posts: 1
Default 1991 Deville ... Instrument Cluster +

Problem... Instrument cluster went out along with heater/ac control/ fuel and mileage status displays... Sometimes I would get a very faded led display but then it would go away after a few seconds... now I get nothing..

Attempts: Tried switching out Instrument Cluster (Speed / mileage etc), no change.
Tried changing computer module.. That brought back a weak display for a few seconds, but then lost any display..

I am an electronic tech but not an automotive one. I suspect heater control module is loading down power supply, but I don't know how to get to that, to try disconnecting to see if problem clears or to trouble shoot voltage levels under load with boards connected and then unconnected to isolate problem. I am afraid I am blowing the ECM Computer module and the 2nd one is bad because the weak temporary display on the instrument cluster reappeared when I put a new module in, but then no display again. Fuses are ok. So I don't know whether I am not getting voltage out of a power supply somewhere, or one of the modules I haven't replaced is bad and loading down the voltage. Where is the module I am looking for and how do I get to it, and/or does this make sense to anyone that knows what they are doing?
Related Topics
Thread Starter
Last Post
Cadillac Deville
07-20-2017 01:14 PM
Cadillac Deville
01-01-2007 01:28 AM
Cadillac Deville
11-29-2006 05:20 PM
Cadillac Deville
10-26-2005 06:42 PM
General Tech
11-21-2004 05:10 PM

Thread Tools
Search this Thread
Quick Reply: 1991 Deville ... Instrument Cluster +

Featured Sponsors
Vendor Directory

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.