Alphasonic PROT Mode...

[oldmako]

Hello gents,

I just bought my kid a 2000 Xterra with an Alphasonic amp in the back powering a sub and 4 door speaks. I have only looked at the unit for a very brief period when the unit wasn't playing. The PROT light was on and the power light was off. The fuses are fine.

Later she went over a speed bump and it came on. Then off again. I had the battery disconnected for a period when I was doing some routine maintenance not associated with the stereo. When I replaced the ground, we had no tunes and another PROT light.

This sounds to me like there is a loose ground or wires shorting out. The owners manual is pathetic and offers very little by way of guidance. It suggests that the amp is too hot and needs to cool, but it's not hot at all. We were listening at very low volumes and not banging heads.

Any suggestions on what I ought to do besides look at the connections on the amp?? The individual speaker wires and connections between the preamp and amp are buried and a mile apart, so they will be a pain to check. There is also what looks like a crossover of some sort under the pax seat. Now that I think about it, that mother isn't bolted down. I suppose that it might be contacting something and allowing the circuit to short and bring that light on.

Any other ideas??

Thanks in advance for any help.

[the converted]

It does sound like it has a short in a speaker wires somewhere along the way. I guess your best options is to get a multi-meter our and figure out which speaker it is on and then troubleshoot just that wire out.

[oldmako]

That's what I feel as well. I had her secure the crossover under the pax seat and it had no effect so I suspect that the problem lies elsewhere. I may get my hands on the car this weekend and if so will just have to start tracing wires and find the fault the hard way.

Should I use an ohmmeter to test continuity?

[the converted]

Definitely get an ohm meter, should be able to find one for under $10 at radio shack or walmart. You're going to be looking for around 4 ohms on speaker wires, and also check that you have no continuity to ground. Let us know if you have any other questions.