Was driving my 1997 GLT wagon last night and the service engine (not the error code) light would come on for 15 seconds or so at which time the radio would turn off. Happened around 5 times in a half hour. The engine actually turned off during one episode but I was able to immediately restart it. After stopping for a couple hours I found that on the restart, I had to reset the radio security code. No more occurrences on the drive home. Any ideas what I should look for?

 

I'd start by looking at the wiring diagram (volvowiringdiagrams.com may have your model) to see if there's a relay or a CEM in the path (thinking it could be overheating) or you may have an ignition switch on its way out. The reset radio is telling you the 12V to power the radio dropped to zero (as if you pulled the battery out).

 

Thanks for the reply. I'll give that a try.