[aso899]

The mirrors do not defrost. I checked fuse panel, nothing labeled for mirrors. Cigarette lighter fuse burnt out, changed, still no mirror defrost. When I activate the defrost function the light adjacent button comes on, indicating system is working?? I live in Maine and do not park in garage. Mirror defrost not luxury, but needed tool. Any help?

[TxGreaseMonkey]

When I bought my Civic new, back in 1993, the rear window defroster wires would not heat. I simply disconnected the rear window connectors, cleaned with Norton 240 grit abrasive cloth, and sprayed with WD-40. They have worked ever since.

See if you can locate the connectors going to your mirror and clean them. Afterwards, I would apply a thin coat of silicone dielectric grease to the male connector(s). The constant heating and cooling fosters corrosion, which you may not even be able to see.

Other, more involved, thoughts:

1. Check not only the under-dash fuses, but also the under-hood fuses with a test light or multimeter. Under-dash fuses are always located in dark, cramped quarters, making it easy to replace a fuse in the wrong slot and really cause problems. That's why you really want to use a test light or multimeter.

2. Check for voltage between the positive terminal and body ground with the ignition switch and the defogger switch ON. There should be battery voltage. If there is no voltage, check for a faulty defogger relay or a faulty defogger switch.

3. Check for continuity between the negative terminal and body ground. If there is no continuity, check for an open in the defogger wire.

4. Check for a poor ground.

My "arm chair" analysis: Since the defogger does not work and the indicator light does not go on, I suspect 1) a blown under-dash fuse, or 2) a bad defogger switch, or 3) possibly a bad defogger timer circuit input, which could be in the defogger switch.