I have a 1999 Blazer which I have owned since 2008. It has started having a battery run down problem.

I located the problem to fuse #19 which is the radio and the instrument cluster. I removed and disconnected the radio and still saw almost a 1 amp draw on the circuit. Disconnected the instrument panel connector (the one at the top center), and lo and behold, no more load on the circuit. Of course this also made all the gauges not work.

I do have a 2-way radio that is in the car (wired directly to the battery and not connected to ANY other wiring )which has a case of alternator whine. Could a bad alternator be the source of my phantom draw? Or am I looking at buying a new cluster? Everything else works fine aside from the almost 1 amp draw.

I do have a strong electronic background so removing and testing things is not a problem

Thank you for any help.


Howard

 

THIS POST should help you out. Found using "battery+drain+RDO+BATT" in the search feature (without the quotes).

 

My apologies for the cross posting.

From what I have read off of the link that you sent, The following need to be checked 1 interior lights, 2rear tailgate latching. If both of these are operating properly, then it would appear that the BCM is at fault? If I want to pursue looking at wiring to and from the BCM where would I start? I know some of the wires carry data signals, and require caution when testing them.

Any possibility that the cluster issue is related to a possibly bad alternator?

Thank you.


Howard

 

I have checked the interior lighting, and the rear hatch release, no problems found there. I subsequently found and disconnected the BCM the ammeter ( Fluke 79 in 10 Amp mode) was still showing between 0.6 and 0.8 amps on circuit #19.

Any other ideas? I dont want to just go and buy a "new" cluster and find out that I was missing something.


Howard