Bad Ground?

[A-Roids]

Hey

So I have a RF p325.1 mono amp... was working fine until a couple days ago when the amp suddenly wouldn't work. I checked all the connections and fuses and they were all solid, but when I checked the ground, there was a lot of rust on the spot I used in my trunk for the ground connection. I figured all I needed to do was get rid of the rust and it would be back and running, so I cleaned it up nice, and rewired everything. The amp still wouldn't turn on, but here's the weird thing, I unhooked the ground wire again, took a call, and forgot to re attach it to the body of the car, when I turned on the car the amp turned on with the thermal light on. I thought it was a sign that the amp was fine, but when I re-attached it to the body of the car it wouldn't turn on at all? Is this due to a bad ground wire, bad grounding area, or a blown amp?

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[dB-SPL 10+ year member]

Scrape some paint/primer off and hold it to a bare metal surface. Without rust.. Use a meter and see if you're getting 12V (with car off in acc position) across the pos. & neg. cables. If you are and the amp doesn't turn on, could be a power supply issue or could be output transistors. run that test first and see if you're even getting power

 

[KyleBechtold 5,000+ posts]

open her up if you want to save time.. if it smell burnt and you see something burnt its blown..

 

[A-Roids]

Scrape some paint/primer off and hold it to a bare metal surface. Without rust.. Use a meter and see if you're getting 12V (with car off in acc position) across the pos. & neg. cables. If you are and the amp doesn't turn on, could be a power supply issue or could be output transistors. run that test first and see if you're even getting power

So If I'm not getting 12V across it I need a new battery? Kind of a newb about this, I would just get someone to look at it but I don't wanna spend like 100 bucks if it's just a bad grounding area. Plus it's more fun doing stuff yourself =)

 

[dB-SPL 10+ year member]

So If I'm not getting 12V across it I need a new battery? Kind of a newb about this, I would just get someone to look at it but I don't wanna spend like 100 bucks if it's just a bad grounding area. Plus it's more fun doing stuff yourself =)

No. If you're not getting at least 12v at the amps terminals then that means you have a bad connection somewhere within the power cable/ground cables. If your car still starts, lights come on etc. your battery is fine.

 

[A-Roids]

No. If you're not getting at least 12v at the amps terminals then that means you have a bad connection somewhere within the power cable/ground cables. If your car still starts, lights come on etc. your battery is fine.

Ok so i picked up a voltmeter thing, it only has settings of DCV 10,250,500 ACV 10,250,500 and DCA 500u, 10m, 250m. I tried looking through the forums and all i could come across was to put it at DCV 20 which I don't have. Should I put it to DCV 250? and also do i put the red prong in the terminal where the power cable comes into the amp and the black prong in the terminal where the ground cable comes into the amp? thanks for the help

 

[PioneerSPL1990 10+ year member]

DC V 10 . it just is 10/20 ect up to 99 for the placement. if you measured on 250 on a regular car you would end up wit 1.44V instead of 14.4V

 

[A-Roids]

DC V 10 . it just is 10/20 ect up to 99 for the placement. if you measured on 250 on a regular car you would end up wit 1.44V instead of 14.4V

Alright so I tried using the Voltmeter, and I got no reading when i put the red prong into the B+ terminal on the amp and the black prong into the Ground terminal. Am I doing it wrong, do I have to open up the amp? Also it's an analogue voltmeter thing, so does that make a difference?

 

[snb778 5,000+ posts]

did the meter read 0.0 or OL

 

[A-Roids]

did the meter read 0.0 or OL

It's an analogue one so the dial didn't move at all