It's possible the connection to the accessory bus (the "ignition sense"
wire) is not contacting well any more. We see this a lot in our 2-way radios
at work when the installer doesn't make a good connection at the fuse block.
The wire in our radios (and maybe yours) is looking not so much for the
voltage but for the transition from voltage to not voltage, and being open
allows them to do what they want.
If it's a factory installation I don't have any more advice, but if it is an
aftermarket installation I'd advise looking at the connection where the
radio is wired into the car. If they are those squeeze (parasite) connectors
I recommend replacing all those buggers with something else... anything
I'll bet you are very close to the problem. I recently replaced the
accessory fuse and radio fuse with the correct values. After the last
problem with the radio coming on, I pushed on the fuses to make sure they
were seated properly. The problem hasn't replicated itself after that. This
might have nothing to do with it, but it's an intermittent and I'll post
back to you in a little while.
Most recent retrofit updates and experiments, etc:
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.