Odd problem, sub only works sometimes

[Nevalite 10+ year member]

Well I tested the coils with my multi meter and they seem to be reading almost 0, but I think my multimeter is playing tricks on me, I'll try my friends one tomorrow... How could they read 0 but then move when I hook up a 9v battery?

I tried new RCA it did the same thing.

I'll try the remote thing tomorrow, good idea.

 

[Nevalite 10+ year member]

If the remote were shorting out the amp would be turning on and off..it stays on whenever the HU is on like it should...

 

[Nevalite 10+ year member]

Well I was using my multimeter wrong, turns out that each coil is reading 4 ohms and they read 2 ohms in parallel.

SO:

-The sub is not the problem

-The battery is not the problem (amp never goes into protect)

-Remote turn on is not the problem (the amp stays on when it needs to be on)

-I have tested 2 HUs and they both do the same thing (probably not the HU)

-I have tested new RCAs (same thing)

-I made a new ground

-I checked all the fuses

-I re-wired the box and the speaker wire

Now it would seem the amp is the only thing left...How could I test if the amp is working? BUT I tested the RCAs for voltage and it seems they are only giving .1v into the amp (much too low), which points to the HU but then again I tested 2 and they both did the same thing.

What could be causing the HU to not give its RCAs enough voltage other than the HU itself?

 

[Macklessdaddy 10+ year member]

Well I was using my multimeter wrong, turns out that each coil is reading 4 ohms and they read 2 ohms in parallel.
SO:

-The sub is not the problem

-The battery is not the problem (amp never goes into protect)

-Remote turn on is not the problem (the amp stays on when it needs to be on)

-I have tested 2 HUs and they both do the same thing (probably not the HU)

-I have tested new RCAs (same thing)

-I made a new ground

-I checked all the fuses

-I re-wired the box and the speaker wire

Now it would seem the amp is the only thing left...How could I test if the amp is working? BUT I tested the RCAs for voltage and it seems they are only giving .1v into the amp (much too low), which points to the HU but then again I tested 2 and they both did the same thing.

What could be causing the HU to not give its RCAs enough voltage other than the HU itself?

Can you borrow a friends sub and test it?

 

[Nevalite 10+ year member]

None of my friends have sub but even if they did it wouldn't change anything, I have determined that the sub is not the problem.

 

[Nevalite 10+ year member]

What could be causing the HU to not give its RCAs enough voltage other than the HU itself?

 

[Nevalite 10+ year member]

I just hooked the su up and put it back in its box after having done all the Ohm tests and it worked perfectly for the first 5 minutes, after about 5 minutes it stopped working again...

I'm going to test the RCAs for signal again, I should be getting like 1v AC right?

I'm sure I will get the same readings, 0.1v, so the question remains: What is causing the HU to sometimes give and sometimes not give signal to the RCAs? Consider that 2 different RCAs are doing the same thing so I don't think its the HU itself.

 

[Nevalite 10+ year member]

Ok guys I have finally figured this all out...

The HU is putting out signal to its RCAs, I measured it with a DMM and at 75% of the HUs Max volume on a 50Hz tone I was reading about 0.7v, I realize this is low but it's because the RCAs I have are pretty crappy quality, that is not the problem. I will nonetheless upgrade these RCAs soon now that I know how bad they are.

I have tested the sub with an Ohm meter and both coils read 4 Ohms + the sub moves with a 9V battery so the sub is fine.

The battery is giving the amp 13.65 volts and there is nothing wrong with the remote turn on wire, so the electricals are not the problem.

Basicly I have tested everything possible and the problem HAS to be the amp itself, it is getting signal from the RCAs it just simply isn't putting out anything to the sub. I will be ordering a new amp asap.

Before I go and order a new amp does anyone have a clever way of testing an amp other than trying it in someone elses system??

Thanks for all the help