Question about Pioneer GM-5300T Car Audio Amplifier
I just installed a Pioneer GM-5300T amp in my girlfriend's car (1999 Pontiac Sunfire). When I completed the installation everything worked properly (i.e., sound was coming from the subwoofers). However, as my girlfriend was driving back home, the sound abruptly stopped emitting from the subs (she had been driving approximately 30 minutes when it happened). I checked all of the fuses (they were fine), all of the connections were tight (including the ground), the speakers did not appear to be blown, the power wire was not crimped or severed. I noticed that the power indicator was lit, so power appeared to be feeding to the amp. Honestly, I'm stumped...I don't know what is wrong. I mounted the amp on top of the speaker box. I grounded the amp to a metal plate extending down from the top of trunk ceiling (not the trunk lid!) - I made sure to scrape the paint away from the metal for a good ground. The only concern I had was the in routing the power wire, I had to run it fairly close to where the exhaust pipe connects to the exhaust manifold (it was about 3 inches away from the pipe), however, I covered the power wire with a wire loom to protect it from heat. Like I said, everything worked just fine when I hooked it up, and it worked for about 30 minutes as she was driving home, then the sound just stopped coming from the subs. Any help, guidance, and/or solutions would be GREATLY appreciated. Please email me with any suggestions.
Apart from the external DC power fuse (I hope you have one in-line), the majority of in-car amps have 2 mini fuses inside the unit to protect the output MOSFETs from overloading due to incorrect speaker connections, ie, if the output impedence is rated at 4ohms, anything less than that is considered to be a short circuit, and will overload the MOSFETs. After performing the tests suggested by KaeZoo, open the unit and look for printed markings on the circuit board, something like F1, F2, the fuses may not look like conventional fuses.
Posted on Jun 12, 2007
You'll need a digital multimeter to do any real troubleshooting. There are two tests you should try that might help you find the problem. First, while the system is playing, test for DC volts at the ground and positive power terminals on the amp. Place the black probe on the amp's ground terminal and the red probe on the B+ terminal. You should get a reading of around 12 volts or more. If you get a much lower reading, then try replacing the main power fuse at the battery. Some fuses, especially AGU (glass tube) type, can fail even if they don't look blown. The next test is to disconnect the speaker wires from the amp and test the resistance through the speakers. If a subwoofer has a damaged voice coil, it won't be apparent from inspecting the sub. You might find an open coil (no continuity through the subwoofer) or a shorted coil (close to 0 resistance through the subwoofer). In either case the sound will stop. If you find one of these, check inside the sub box to make sure it's not just a loose wire.
Posted on Jun 11, 2007
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