posted
I've blown a 100 amp and a 60 amp anl fuse under the hood. All I have hooked up to it is a PG ZX475ti. 4 awg straight back into the amp. 4 awg ground. first 100 amp blew when I connected the power to the amp. 60 amp anl blew when I put it into the fuseholder to replace the 100 amp. I checked for damaged casing on the power wire but it's ok the whole length. the power wire passes through a fat factory grommet and isn't close to getting cut. I checked it anyway and it's ok, too. Why does the fuse keep blowing?
posted
If your blowing a fuse without even turning the headunit on, I would say you either have a short in the wire, the 2 wires at the amp backwards, or a very screwed up deck
I wouldnt keep putting fuses in until you find the problem. It may get expensive, not just in fuses but in blown equip, melted wiring, etc.
------------------ Nathan Munson Eastern Audio
Worlds Loudest Certified 1 woofer DB Dragster -- 167.3 at Padre
posted
To verify the condition of the wire, remove the wire from the amplifier, and check for continuity to chassis ground using a multi-meter set to read resistance. Look for any resistance to be measured, if there is any action on the display, you probably have a short along the wire. If this test shows no connection to the chassis at any point, go back to the amplifier and confirm that the connections are made in the correct polarity. If the polarity is correct, then the possibility that you have a bad amplifier is high. As I suggest to all my installers, don't assume anything, physically check everything twice. Good luck, and keep us posted.
posted
I noticed in your link in your signature you say you have a couple of 1 farad caps, but here you say it hooked directly up, so just an idea, if the caps have been discharged, and not charged with the resistor they will short, and cause the fuse to blow, my installers have done this before, and thought it was the amp, but I have had the same happen with amps too. So just somthing to check, if the caps are still in there.
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Posts: 515 | From: Omaha NE, USA | Registered: Nov 2000
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posted
The caps aren't in right now. Are there caps in the amps too? I tested for shorts by checking the resistance across spots. what I got was kind of weird. Touching the ground terminal on the amp and a grounded screw obviously gave me little resistance. but if I touched it to the power side, I forgot around what it read, but the resistance kept slowly rising. I disconnected the amp and taped off the ends of the power wire. I tested it again and it didn't read anything from the power wire to a ground so I guess there's no short?
posted
There are usually caps inside the amplifier as well, but not usually enough to draw the amount of current to blow your 100a ANL. If you've tested the wire and found no shorts to ground, I'd suspect the amplifier has a problem inside. To verify this, have the amplifier bench tested at a shop, just a simple power and output test will suffice.
posted
Try checking the resistance between the + and - terminals on the amp, without any power or ground cable connected. If you get a low reading, kiss the power supply in the amp good bye. Time for service. If you get a high reading, then the short must be along the power wire or maybe the connections at the amp are too close for comfort. Check the power wire by itself: no fuse or connection to the amp. This has to give you an infinite reading. If it doesn't, then you might have inadvertently pinched the power line with a screw along the car or a tight squeeze by a pannel. In order to instantly blow a 100a and a 60a fuse, there has to be a dam good short somewhere. Must've scared the pants off your neighbour's cat with the spark!!
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