I bought her a new stereo for it for Christmas to install in her 1995 Blazer. It already had an aftermarket unit in it so the install was very simple. Everything seemed just fine except that at high volume levels it would just turn off. It would go black like it had no power to it at all and then it would come on 2 seconds later but if you didn't turn the volume down it would cut out again. It played fine as long as it wasn't at a high volume level. I thought maybe it was some kind of safety switch or something to prevent the speakers from being blown or something but it mentioned nothing about it in the manual or online.

It was bothering me why it did that but what is really puzzling me now is that my daughter came home late last night and said when she turns her headlights on, the stereo shuts off. It only works with the lights off. I'm thinking there's got to be a loose connection somewhere but there's just not too many places to check. There's a constant power, an accessory power and a ground.

I'm going to pull the unit when i get home tonight and check them all but do any of you have any ideas of what my be the culprit?

 

I know you said there is constant power, but it sounds a little like clipping at higher output. Does the system have seperate amps, or are you running off the H/U only?

Have you done the big 3? A little more info on the system used may be helpful.

 

Its just powerd from the internal amp in the H/U. All I did was swap the H/U with the one that was previously installed using the new wiring harness that came with the new H/U. I originally thought it was a clipping issue but the fact that the unit also just shuts off as soon as the headlights are turned on baffles me.

I took the unit out last night to check all the connections and they all seemed fine. I plugged it back in and it wouldnt even turn on. It was about 10 degrees last night so I didnt want to mess around with it out there. I unplugged the wiring harness and brought it inside and I noticed that the black wire (ground) where it inserts into the plug was out further than all the rest of the pins. I grabbed it and it pulled out with no force at all. Maybe I'll just ground directly to a metal part of the truck to eliminate the possibility of a bad ground. I know a bad ground can cause all kinds of issues.

By the way, what are the "Big 3"?

 

Okay I solved the issue. From the way it was acting it had to be a ground issue. After a few minutes of checking connections and still having the issue I stumbled across the problem. I looked at the plug and it had room for 6 wires but only 5 were used. There was an empty slot. I looked at the wire in the plug coming from he truck and there was a power wire, a switched wire, an empty space and then the dimmer, power ant and then the ground (1, 2 space 4,5,6). On the plug adapter coming out of the radio all the wires were together and the space was at the end (1,2,3,4,5, space) so the ground was not connected at all. I pulled the dimmer, power ant and ground pins out of the connector, moved them over one spot and everything worked great.

 

Great.

Oh, and the big 3 is upgrading the Battery to Motor, Motor to Chasis, and Alternator wires to a heavier gage. I went with 00 and it helped my system quite a bit. Just search on here. There are several how to articles.

 

Thanks for the info on "The Big 3"

 

actually if you look straight down on the right side of the battery there is a nice factory ground you can clean up and use. also i used a nice bolt on the left side of the alternator (engine ground)

Canadian tire has a big selection of different battery cables i think in 1 gauge and 4 gauge if you dont want to buy wire, ring terms. and solder them, although it is fun