Battery draining/Alternator good

[mdawnsmith]

94 PA 150,000+ miles, runs great, no major problems for 3 years .... until now. Battery tested and good. Alternator tested and good. Starter tested and good. All 3 replaced (brand new) about 2 years ago. History: Heater control module died last summer. Blower stuck on with no controls. Pulled fuse - solved blower problem but no heat, no AC. No biggie - I live in Michigan. Weather changes hourly.
PROBLEM: Battery won't hold a charge. Battery & Alt. are good and car will start when jumped and runs fine. If left for several hours/overnight ... battery dies. I suspect a short draining the battery. Where should I start looking? Could it have something to do with the heater control module?

[HotZ28]

{Quote} "Could it have something to do with the heater control module"?

The answer to the above is no. If you pulled the fuse to that circuit, it is dead! By the way, I don't see how you drive without a blower motor working!


If you check with your local bone yard, you could get a module for about 50 bucks, or a new one for about 100 bucks at Advanced Auto Parts. Of course, thats your call.

It is very simple to track down a battery drain problem; you first need to see the drain. Your tool could be either a volt meter or you can construct a light bulb with two leads so that it will glow when there's electricity flowing.

Procedure:
1. Disconnect the negative battery cable from the battery.
2. Wire the two leads of either the voltmeter or light bulb tool between the disconnected battery cable and the negative battery post. You should see the battery drain at this time on the voltmeter (or see the light bulb tool lit).
3. Pull the fuses in the car one at a time, and observe if the battery drain stops. When the drain stops, you've found the problem circuit and need to investigate why.
4. If you've pulled all the fuses and saw no change, the problem circuit may be one with no fuse in it like the alternator or starter circuit. You would need to disconnect them manually to test.

[Alibi]

This may sound silly, but it is possible that your dynaride is acting up and not shutting off overnight?

I had a very similar problem to yours and I discovered that my dynaride would kick on enough overnight to kill my battery.

Just a thought.