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From time to time, folks ask questions concerning (possibly excessive) current draw when trying to diagnose a mysteriously draining battery problem.
So I thought some of you might want to make a note of the following.
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background: I recently had occasion to remove my instrument panel to swap the clock for a (80mm) tach. In doing so, I made an effort to measure the current draw (a VOM in amperage mode, across the battery's neg. post and the negative cable as it was disconnected), both before, with the clock, and afterward, without the clock. I thought this would be a good reference to compare to your car (if it's somewhat like a '93) if you begin having battery draining problems.
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All of the figures are in standby condition (no doors open, no interior lights or any other accessories on, and the key is not in the ignition. Also, in both modes, I was able to carefully lift off the cable (keeping the VOM maintaining continuity) so that the radio wasn't cut off (it didn't need a code input), in case that might effect the radio's memory's need for current.
With the clock installed, I found the current draw to be about 11 or 12 ma (0.012 amps) -- the digital readout jumped a bit. But I also noticed occasional spurts to about 20-25 ma. They were so brief, however, that I'd estimate that, overall, the time-weighted average was hardly higher than the somewhat more steady 11-12 ma -- use this as your reference.
With the clock removed and replaced by the tach (which isn't on when the engine isn't on), the drainage diminished and remained rock steady, at 7.8 ma (0.0078 amps).
In retrospect, therefore, the clock was probably causing the current fluctuations (maybe some stepper motor?).
And this 7.8 ma drain is probably attributable to the radio's memory presets and whatever memory the engine's ECU (or whatever it's called) needs to retain diagnostic codes, etc.
Hope no one has battery troubles, but if you do, you can use these figures as a point of reference, for comparison. Remember, though, that this is a '93.
Regards to all.
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