This is my first attempt at installing an amp. It's a small 400w Pioneer amp. I've done lots of household electrical work and a lifetime of computer builds, so I feel I'm fairly competent with electronics
I've installed plenty of head units, however, this is my first attempt at installing an amp...
When I turn on the ignition, the amp's light turns on then off quickly.
I've checked all fuses, everything's good.
Here's the strange part (strange to me I'm hoping it's obvious to the experts out there)...
I've got my multimeter out and I'm taking readings. With the car off, the reading at the battery is about 12.67V. The reading at the amplifier is about 12.55V. If I turn the key (don't crank the engine, just turn on ignition), the amplifier tries to turn on (the light flashing on/off) and my reading at the amplifier drops to 8V. (So it's obvious the amp won't turn on with only 8V, but not obvious to me why there's only 8V at this point.)
If I turn off the key, it slowly builds back up to 12.55V (takes about 2-3 minutes).
If I remove one of the leads to the amp (power or ground), then my reading at those leads immediately jumps to match the reading at the battery (12.67V).
The behavior is the same (albeit with higher readings at the battery) if the engine is running.
To me, this is strange. I'm hoping it's an obvious symptom of a problem and that someone can point me in the right direction for diagnosis.
UPDATE: Diagram: http://yfrog.com/13wiringg