98 Tahoe amp/sub help
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=26138
Printed Date: May 13, 2024 at 5:14 PM
Topic: 98 Tahoe amp/sub help
Posted By: Kayak Jones
Subject: 98 Tahoe amp/sub help
Date Posted: February 09, 2004 at 12:35 PM
Did I do this right or did I screw it up. JBL 1200.1 mono amp. 98 Tahoe with oem alpine. 4g power from the amp to the +batt terminal. ground from amp to luggage tie down in rear of vehicle. Remote wire from amp to blue wire in alpine wiring harness. Result:no power to amp. Switched remote to blue/with white stripe wire. Got power and promptly began blowing fuses in the amp. Never got sound. just blown fuses. Any ideas from the gurus would be greatly appreciated.
Replies:
Posted By: Teamrf
Date Posted: February 09, 2004 at 1:21 PM
Gheck your wires....you always want to use the blue with white on the back of the radio for your remote turn on wire. The other wire is your power antenna. Your ground may not be good. Make sure you have scratched all the paint of the ground, and made a good connection. Make sure you are also not drilling into lines in your car (gas line, brake line) Also check your fuse under the hood.
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~The Rookie~
Rookie of the year that is...
Don't let the smoke out of your equiptment..it doesn't go back in.
Posted By: Kayak Jones
Date Posted: February 09, 2004 at 1:50 PM
I have switched the remote to the blue/white wire. thats when the fuses began to blow. Possibly ground related? Power line fuse to amp (inline 100amp is good) just the three 40 amp fuses on the amp itself are blowing. Assuming the ground is good, would speaker wiring to the subs have anything to do with this, and if not ,possibly bad amp?
Posted By: forbidden
Date Posted: February 09, 2004 at 2:12 PM
Disconnect both the rca cables and speaker wires from the amp. Power the unit on / off again, if it still blowing fuses, it is a bad amp. If it is good, plug in the rca cables, if it blows fuses, chances are the rca cables have been clinched and are going to ground. Run a new temporary rca cable and see if the fuses still blow. If they do, chances are that you have a bad input stage in the amp. If the amp is Ok still, have a good look at the speaker wiring to see if it is going to ground as well. ------------- Top Secret, I can tell you but then my wife will kill me.
Posted By: Kayak Jones
Date Posted: February 09, 2004 at 2:32 PM
I'll give this a try this evening and let you know. Thanks for your suggestions.
Posted By: Kayak Jones
Date Posted: February 09, 2004 at 2:39 PM
One more thing. The amp has to sets of terminals for speaker outs, 2 pos and 2 neg. With single voice coil subs 4ohm each, what are my wiring options for the subs (assuming i can get the@#$ ting to work). It is 2 ohm optimized and 1 ohm stable.
Posted By: customsuburb
Date Posted: February 09, 2004 at 6:23 PM
if you wire 2 4ohm subs to the single output of your mono amp you are going to be getting a 2 ohm load(this should be fine as long as its not too much power for your speakers).
Posted By: customsuburb
Date Posted: February 09, 2004 at 6:26 PM
sorry i was thinking of a mono amp. if your amps 4 ohm 2 channel output isnt too little power for your subs each then just connect one sub to each channel. otherwise you are pretty much out of luck unless your amp is a mono amp that has two sets of mono outputs. if this is so then I would just connect one sub to each terminal to get a 2ohm load.
Posted By: Kayak Jones
Date Posted: February 09, 2004 at 7:31 PM
Update: Unhooked all speaker and rca cables. Re wired ground to a good source (seat belt bolt). Checked remote wire. (good voltage). Turned on car, blew 3 fuses. Checked all terminals with meter (all ok). Checked power wire for short (nothing visible and excellent voltage to amp)). Started vehicle, blew 3 more fuses. Checked everything else we could think of, then ran new direct power wire from amp to battery. Touched new wire to + terminal. Loud popping noise followed by smoke and OH SH#T, SOMETHINGS BURNING smell. The general consensus was that the amp was bad to begin with, because we couldn't find any other problems. If it wasn't, it dang sure is now. It was a refurbished JBL BP1200.1. Called the dealer and am taking it back tomorrow for a refund or exchange toward a different amp. Did we miss anything anyone else can think of and either way, thanks for the prompt input.
Posted By: Kayak Jones
Date Posted: February 12, 2004 at 11:56 AM
Update: New amp works fine EXCEPT that rear door speakers were not working after amp install. They were working fine before and no wiring changes were made to install the new one. (the system was already wired for the one that was blown) now mind you that the speakers only didn't work when the cd was playing, they worked fine on fm. Also, Could not get any am radio reception after powering up the amp. So, I switched the rear door speakers wire to the blue/white stripe wire that the remote turn on for the amp was wired to. presto, everything worked fine. Until this morning that is when all of a sudden I lost am reception again, (fm ok) plus the rear speakers are still working fine. I am stumped. Any and all suggestions welcomed.
Posted By: forbidden
Date Posted: February 12, 2004 at 1:10 PM
Some gm vehicles have a antenna amplifier that also needs to be given a 12 volt signal, is yours one of them, I cannot be sure. Did you have am reception before powering up the amp? Do you have another wire in the factory harness that when the factory radio is in reads +12v when the tuner is used? Most factory radios have an amazing tuner in them, most aftermarket do not. FM radio is pretty much not bad for any aftermarket but AM leaves a lot to be desired. The last time I ran into this kind of problem it was in a 03 Buick Regal and it had the hidden antenna module, once this module was powered up, presto, AM reception again.
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Top Secret, I can tell you but then my wife will kill me.
Posted By: Kayak Jones
Date Posted: February 12, 2004 at 1:19 PM
The am radio reception was fine prior to powering up the amp. Nothing was done to the wiring harness that had not already been in place for many days. FM reception is fine.
Posted By: italnpimp59
Date Posted: February 12, 2004 at 1:25 PM
you gotta power the blue wire coming off the aftermarket GM harness. it turns on a factory amp that runs your back speakers..ive seen this before. so the remote wire to ur amp, the blue wire on the GM harness(even though it may say power antenna) and the blue/white wire remote output on ur headunit all need to be connected together
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Posted By: Kayak Jones
Date Posted: February 12, 2004 at 1:41 PM
the wiring is as follows. Remote from amp wired to blue with white stripe wire. Rear speaker wire (back door only, not rear deck) also blue, is wired to same blue/white wire. The rear door wire was moved to the blue/white wire yesterday after the rear door speakers wouldn't work on cd, and the am radio reception was non existent. That fixed the problem. Until today, when the am reception is gone again. all else is working fine. The only wire that is currently not being used is another blue one that the rear door speakers were connected to as of yesterday. They worked fine until the amp was powered up. That blue one is now capped.
Posted By: Kayak Jones
Date Posted: February 15, 2004 at 12:31 PM
Update: The problem ended up being a bad section of coax wire. I had the section repaired once previously and with the multiple removal/re-installations of the head unit the repair failed. All is well now. thanks for everyone's help.
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