prince xizor

iTrader: (2)

I have a 99 Trans Am. I finally got around to installing my amp for my sub. I have never had any trouble with the stock radio until I installed the aftermarket amp. When I am playing the radio, all sound cuts out of the head unit. No tweeters nothing. It seems to happen at higher volume when I am trying to set the amplifier up. It doesn't seem to to do it at lower volumes. I have been able to get it to stop working when in playing the cd player and the radio. The CD will keep the time moving and you can change stations but there is no sound. If I turn the car off, wait and restart the car, then restart the radio, I can get sound, I just need to turn the radio back up.

I ran 4 gauge OFC wire from battery to the back passenger wheel well. I tapped and soldered into the pink antenna wire for the turn on. I tapped and soldered the rear speaker inputs on the monsoon amp for the high level inputs using 12 ga speaker wire. I am grounded with 4 gauge near the power antenna ground. I have the gain set to the minimum with the lowpass crossover around 90 hz. I used my multimeter and saw that the high levels are making about 2.5v AC. I am getting about 13.8v DC at the amp and ground. My output on the amp is 15v AC.

For troubleshooting, I have :
1, Amp hooked up, starts with sound and then cuts out on CD
2. Amp hooked up, starts with sound, then cuts outs on Radio
3. Amp disconnected at battery, starts with sound and cuts out on CD
4, Amp disconnected at battery, starts with sound and cuts out on Radio

I searched the forums and it seems like the common issue is with the BCM. I have got it to cut out but can still operate the windows. That means it isn't the BCM. What should I look for next? I tested continuity on the fuses for Radio, Steering wheel control, courtesy, radio accessory, steering wheel control and all check good, The 20 amp fuses in the amp and wire are also testing good. Any ideas?

WhiteBird00

iTrader: (4)

If I read this correctly, you basically have an entirely stock Monsoon audio system except that you have added a line output converter to the wiring at the Monsoon amp in order to provide signal to an aftermarket amp powering a sub? The rest of the speakers are still running the way they did from the factory?

In that case, this would be a head unit problem. It's not a fuse because it comes back later without changing a fuse. It's not the BCM cold solder problem with RAP power because your windows still work. The audio cutting out even when the sub amp is disconnected from power eliminates that amp as the problem. And it's not the Monsoon amp because a Firebird has the tweeters in the doors and hatch area powered directly from the head unit yet those are cutting out as well. That leaves only the head unit.

prince xizor

iTrader: (2)

The rear speaker inputs that I tapped into are going into the high level inputs on the aftermarket amp. I didn't know if that would create a different ohm load that is causing the head unit to cut out.

WhiteBird00

iTrader: (4)

I suppose that would be possible - the 4-ohm input of the Monsoon amp in parallel with the 4-ohm input of the aftermarket amp would give you a net 2-ohm load which might cause problems for the head unit's internal amp, especially at higher power levels. But the same thing happens even when the aftermarket amp is powered off and isn't contributing to the overall impedance so it would still seem to be the head unit.

Maxflihd90

I have the same issue with my 1997 Firebird 10 speaker system (all stock) but did replace the head unit last year (with a remanufactured unit), which did not resolve the issue. I've also removed the BCM and soldered the points mentioned on a few You tube videos. I did have some weird flashing light on the dash, but have not experienced this since the BCM was soldered last year. The sound cuts out once in a while at lower volume when playing a CD.... it always cuts out at higher volume when playing a CD or the radio... its seems to cut out more often when more bass is output... could the issue be power related??? Once it cuts out, I simply turn it off and back on and the CD plays from the same location it left off. I plan to check the wiring polarity since I've installed replacement speakers (except for the tweeters) in each location... they are all 4 ohm rated. The rear speakers are 4" Kickers, the sail panel speakers are new GM original design, and the front speakers are Pioneer 6.5" Coax.

WhiteBird00

iTrader: (4)

This is probably a head unit problem because the 10-speaker system only uses the amp to power the sail panel subs - all other speakers are powered directly by the head unit. So, if all sound cuts out (not just the sail panel subs) then you can be sure it's not an amp problem. This is basically the same condition as in a Monsoon system - the tweeters are powered by the head unit so if they cut out along with the other speakers then it's not an amp problem.