If i sit with my car off, the battery gauge will sit a 10 or 11, but then all of the sudden(no particular time period) it drops below 8. I recently disconnected the smog pump and the ac./ I tape up all the unused connectors, but no luck. Is it a short maybe? I had to replace my floor mountwed dimmer switch (as described in the tech article). Could this be shorting out on the floor pan? The lights still work fine. Any suggestions would be greatly appreciated.

 

Check your alternator. There a small piece
in that cause a power drain on the battery.

 

The drain caused by the radio memory, ECM, etc., should not cause the battery to drain that much even sitting for a few months (I've done it and it has easily remained above 10 volts). If the battery goes that low with the key out in a few days, you'll need to determine how many amperes are being drawn with the key out. You'll need an ampmeter. You should see a small current drain (<120mA) due to the parasitic load (ECM, etc.).

Since batteries can be tested free at many auto parts stores, I'd suggest checking it. They can test it under load which is a good way to test them.

You can test it yourself, but it won't be as good as a "load test" (see above).

With a fully charged battery, turn all the accessories "on" (lights, fan on "high", etc.) for ~20 minutes (or the lights for ~40 minutes). Then, with everything still "on", start the car. It should start right up.

You could also remove the power wires to the secondary ignition coil to keep the engine from starting, then operate the starter for 10-15 seconds. The starter speed should be essentially the same from the start to the end of this time.

[This message has been edited by Stuart Moss (edited June 07, 2001).]