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Hey guys, I need your help. I decided to change out my substage and now I keep blowing fuses in the distro block after I start my car. Here's my old set-up:

Vehicle: JDM 2000 Subaru Legacy GT Wagon (Twin Turbo)

Battery: Bosch Premium (American Bosch Platinum S5 equivalent)

Big 3: Streetwires Ultra Flow 1/0

H/U: Alpine CDA-9887

Front Speakers: Kicker Impulse i525

Amp: US Amps USA-50

Subs: TC Sounds OEM 10 (x2)

Amps: US Amps USA-200 (x2)

**NEW Substage:

Sub: 12" SSA ICON

Amp: US Amps PT-1100

I've got 1/0 going from my battery (200A fuse) to my trunk and running into a 3-way distro block (fuse sizes are 25A, 60A, and 60A). From there, I've got (3) 8 gauge wires going to all 3 amps with 8 gauge grounds per amp. I've never had any problems or blown any fuses in the past 8 years with this electrical set-up. I decided to replace the OEM 10s with a classic 12" ICON and use my PT-1100 (2 power/2 ground inputs) to power it. When I removed all USA-200s, I noticed both grounds were all corroded on the car side (Okinawa weather). I tried to clean up that area with sandpaper and a Dremel but the area was pitting so I drilled 2 new ground holes (about 5 inches from the original grounding points) and sanded/used the Dremel to clean the area up. I cleaned up the USA-50's grounding point while I was at it, too. Afterwards, I covered all the grounds with RTV to prevent rust/corrosion. 

After I got everything hooked back up, I started the car and set the gain on the PT-1100. The amp was working (green power light stayed on). The (2) 60A fuses in the distro bock were fine. I wanted to set the low pass crossover so I used my CC-1. Right after I started setting the crossover, I noticed the low battery light on the CC-1 so I shut everything down and got a new 9V battery. When I started everything back up, I was having trouble getting the CC-1signal light to stay on (flash green then red). It was late at night so I decided to call it quits for the night and would start the next morning. 

This morning I started the car and turned on the CC-1 but I wasn't getting the signal light. I looked for the amp's green power light but it was not on so I looked at the fuses. Both 60A fuses were blown. The amp didn't smell like anything burnt/blew. The 25A fuse for my USA-50 was good. I swapped out both blown fuses and re-connected my battery (fuses were good). I started my car and went back to look at the distro block and both fuses blew again. I unmounted the PT-1100 and inspected it to see if something was burnt or damaged. The amp was good. I took it inside my house and hooked it up to my power supply and it was working without issues. I checked all the grounds for the Big 3 and the grounds going to the amps (0.0 - 0.1). The only thing I did different was moved the 2 grounds (5" from their original ground points) but they're reading 0.1 (good). What do I do next?

 

 

 

 

 

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A little more info...

The amps are in my spare tire housing area mounted on a 3/4" thick Birch cutout to match the tire housing area. When I set my gains, I didn't have the PT-1100 secured on the board with screws. Later, I screwed the amp to the board with 1/4" thick rubber pads between the amp foot and the mounting surface to raise it up for better air flow and vibration dampening. I checked and the screws weren't touching any metal in the housing area (that I could see). I might try and hook it up again, unsecured, and see if it still blows the fuses. I'm going to start using smaller sized fuses (35A) because I have a lot of them if they keep blowing. Any thoughts?

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Have you checked with the ohm's meter that there is no continuity between the ground and power at the 1100's leads? 

Perhaps power was hooked up backwards? Don't feel bad if so, I personally have done this at least once in my life.

 

 

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Posted (edited)

The wires were connected correctly. I checked my grounds again and they were good (.1 ohm). I put (2) 35A fuses in the distro block and moved my grounds back to the original grounding points. They measured 0.1 ohm. I hooked up power and it read 12.85V at the amp. I started the car, with the stereo off, and the fuses were good. It read 13.9V at my amp. As soon as I turned the stereo on, the (2) 35A fuses popped but my 25A fuse to my front amp was good. 

In my previous set-up, I used a tap on my remote wire at the head unit so I would have 2 wires for my amps. This is how my set-up has always been. The remote wires went to my front amp and then to one of my sub amps. The second sub amp had the remote wire connected to the first sub amp and I never had any issues. The PT-1100 has the remote wire connected directly to the amp from the stereo (as does my USA-50). Now, when my stereo turns on, the PT-1100 fuses pop. Should I use a jumper wire from the front amp since it doesn't have any issues? I had to stop troubleshooting because it started to rain.

Edited by firey_kimchi
Clarification

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Something is causing a direct short to ground while in the vehicle and upon powering up.    I've had several times where something works on a test bench, yet when installed, it does not.  It's the most frustrating thing ever because it's simple to work on on the bench. 

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I shot the grounds again, inspected the PT-1100 for broken pieces and touching wires but everything looked good (car side and amp side). I decided to hook up one of my known good USA-200s that I had just pulled out of my system. I had a 40 amp fuse in the distro block and hooked up one set of power/ground wires to the amp along with the remote wire. Everything read good with the battery hooked up (grounds read 0.0 - 0.1 ohm, 12.65V at the amp, and 0.0V at the remote wire). I started the car, with the stereo off, and it read 14.24V at the amp and 0.0V at the remote wire. When I turned the stereo on, the fuse did not blow.The remote wire read 13.45V. I shut it down and disconnected the first set of power/ground wires and hooked up the second set of power/ground wires. The results were the exact same as the first time. I decided to bring the PT-1100 back out and hook it up. The grounds read good, the amp read 12.65V with the battery hooked up, 14.34V with the car on (stereo off), 0.0V at the remote wire. As soon as I turned the stereo on, the fuses exploded (not burned, not popped but EXPLODED). I had glass and fuse particles all over the trunk area with white powder marks on the distro block and amp rack. My USA-50 fuse was unharmed and good to go. 

I looked at the PT-1100's board and there was nothing noticeably wrong with it. Now, I'm 100% sure it's the amp so I didn't hook it up to my power supply. It looks like I'll be sending it in for repair. In the meantime, I'll hook up an SSA IC150.4...maybe permanently!

 

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That's nuts!  I've only seen fuses actually expode on high(er) voltage.

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Bad news...the amp is not repairable. It's got a Tripath chip in it so it's nothing more than a large paper weight now. It looks like the SSA IC150.4 will be my new amp. Hopefully it'll have enough power for the ICON.

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Bummer dude.

Good to hear you figured it out at least. Nothing worse than chasing electric gremlins.

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