1992 Buick Century Battery drained by climate control?

LEROYS1000

MEMBER
1992 BUICK CENTURY
6 CYL
FWD
AUTOMATIC
205,000 MILES

This just started recently.
I have been having a dead battery for a couple
of weeks now.
I heard a fairly loud clicking noise coming from the
engine compartment.
Turns out that even though the climate control
and ignition is turned off, the AC compressor
clutch is engaging and disengaging.
I have disconnected the AC clutch and
the pressure sensor in the AC coolant line.
I am still getting a slow drain and ending up
with a dead battery.
Any idea where to start looking for this short or
problem causing the drain?
Thank you,
LeRoy

2 Replies

JDL

MECHANIC
16,098 POSTS

You didn't say how much amp draw, with the key off, a slight draw is normal.

Did you put a charger on the battery?

As far as the compressor, I'd start at the ac relay. With the key off, take the connector loose, check for voltage at the connector terminals? There shouldn't be any voltage there with the key off. If you find voltage there, with the key off, there might be a problem with the ignition switch or the circuit is shorted to voltage, somewhere. With the key in the off position, you might try to wiggle the key and see if the circuit goes dead. You could pull the fuses and check for voltage, there shouldn't be any with the key off. My info shows H/AC fuse 25 amp and engine/ac fuse 10 amp.