Car Audio Amp Troubleshooting Help

I like that tester, be interesting to see what it can do, thanks. Today we used an old school audio generator to do some signal tracing. The "parts" amp that I got off ebay was in fairly bad shape audio board wise, the power supply seems good. The amps only draw a little over an amp when revving in neutral, we don't put any input, music or signal on them unless we have a speaker on the output.
One thing I didn't notice right away last night was the previous owner put the amp back together with the insulating on top of the power supply vice under the audio board.

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