Need Help TroubleShooting

[mikeycvw]

I am currently driving a 2003 Jetta and aout 2 years back i installed a pioneer navigation with a JBL500 watt amp (don't know the model number off hand, its the one with the clear top) and a JL10w6. Recently, i am only hearing the subwoofer work at random and the only connection i can put together when it does work is when it is warmer weather outside (I know, sounds wierd). When its cold out i get no bass. Sometimes when i turn the car off and then back on again it will work, but the sub doesn't seem to be as powerful. Then there are somedays where it will work just fine and sound great but those are the days its warmer out. The amp always seems to turn on, and there are no error lights upoin start up. I did read in the manual that the amp needs 9V to start up correctly, and i don't have anyone around to start the car while i hold a meter to the amp. Could my battery be going bad and the amp is not getting getting all the power it needs? Alternator? Everything else in the car is working fine. Should I install a capacitor, maybe? If so any suggestions on which one?

Anyone have any ideas?

[Perry Babin]

You need to confirm that you have sufficient power supply voltage. With your multimeter set to DC volts, the black meter probe on the ground terminal of the amp (not on the point where the ground wire connected to the vehicle) and the head unit on (so the amp will have remote voltage applied), touch the red probe alternately to the B+ and remote terminals of the amp. If the voltage is below ~11 volts on either the B+ or remote line, you need to check the wiring feeding whichever line is too low. If 'both' the B+ and remote turn-on lines are low and your battery is fully charged, you may have a bad ground connection.

[mikeycvw]

The system has been working great for 2 years. Can a ground connection just go bad? I own a DMM what should the voltages be at the battery to check that it is fully charged?

[Perry Babin]

Any connection can fail.

[darren69]

I had a car alarm problem like that too when it was cold the car wouldnt start and when it was warm it fired up every time. i think the problem was a worn out switch or fuse link or something that needed to make contact but in the cold (mornings)it would shrink just enough to **** me off and leave me stranded lol

[mikeycvw]

OK, so i moved the ground to the popular seatbelt bolt underneath the rear seat and the first time i fired it up it worked great. The next time i started the car the amp's protect light and I-E OPT light started flashing. I checked the voltages across the ground and power and ground and remote wire and they look good. anybody have any suggestions? I hate being without bass.

[mikeycvw]

Read on some other forums that this meant that the amp was burnt out(it is about 5 years old). Purchased a JL Audio 250/1. I also read that the JBL BPX 500.1 that i am running now is too much for the JL 10w6. Hopefully the JL 250/1 will sound just as good.

[AKHeathen]

take an ohms reading on the sub and compare with Re in the specs advertised specs. if it was, indeed, too much for it, the coil could have cooked, and shorted a portion of the coil. that would throw it into protect...