Got a issue that has been going on for years, but has just recently gotten to the point that I need to fix it. Used to happen once a month or so, now everyday, constantly during the day

Car:
1999 Z28
Aftermarket stereo, radar detector Hard wired, Full audio system (basically just listing for info, two amps, one twelve, all speakers replaced going through amps)

radar detector is wired to the fuse blocks ignition fuse.


The car randomly loses Accessory power. When this happens, while driving/sitting with car running, the power windows don't work, the radio shuts off, the amps shut off, the door locks work, and the radar detector works. It's basically as if I turned the ignition switch off, except the radar detector stays on and usually shuts off with ignition. The radio's constant 12volt stays working as the mask face turns and closes up everytime this happens, (I do not know if power stays on the cig/acc plugs)

When this happens it's random. Sometimes I can go on a drive without it happening, most the time lately it's on off on off on off during the drive, once in a while I can't get it to come back on at all.

I have found that if I toggle the door locks back and forth (the electronic button) real fast I can usually get everything to come back on. It will usually cut off again at another time and I will start to toggle the door locks and after a few seconds get it to come back on.

When the issue happened before I had the BCM mentioned, but since it has gotten worse with the symptom of coming back to life with the door locks I figured I would ask again.

Forgot to mention, nothing had been added for years to the car when this started. And nothing has been added since except the radio was replaced, but that didn't make the issue happen more or less.

 

I know it was mentioned before but it still sounds like a BCM issue due to the radio and power windows not functioning at the same time this happens. I would start with repairing the solder joints on that and see if it helps. It's pretty easy to do so you won't be out anything by trying that first.

 

Cool. If I am correct that item is under the dash in the top right side looking up under the steering wheel, correct? Haven't dealt with that peice before.

I forgot to mention I also have a Viper remote start alarm, it was on it before the issue happened, but thinking about digging through the wires to get to the BCM made me think I didn't mention it.

 

It is behind the passenger glove box. Just remove the kickpanel and pull it out.

 

IMO time to bypass RAP on the BCM

 

That might be a good solution as well. I would try the soldering first because it is a fairly easy thing to do and it has worked in alot of cases (including my own) but if not then the bypass is in order and see how that does.