Electrical (stereo) problem at high temperature?

This is a 1993 Ford Ranger 2wd.



I’ve been noticing this summer that when the engine temperature is warm, ususally when driving at highway speeds on hot days, the stereo gets crackly and then the feed cuts out competely. Sometimes the clock and radio presets are reset when it comes back on (after the engine has cooled). The engine temp gage never goes even very much beyond the “low” range, but I notice this happens more on hot days and/or after it’s been sitting in the sun. I checked the wiring and all seems to be ok.



For some reason it seems to happen more while the window is rolled down, and rolling up the window seems to help, though I can’t imagine why and wonder if I’m imagining it.



The stereo issue doesn’t bother me as much as the possibility that this is an early symptom of a bigger problem (ie. alternator, starter, etc)



any ideas to get me started?

Without seeing a wiring diagram I would guess there may be an accessory power relay going bad, or maybe a bad fuse socket, or possibly a corroded connection in the wiring harness somewhere. I’d find the fuse first and try swapping that out. Some oxidation buildup in the fuse socket could be causing this, though it’s unlikely, but it is a cheap thing to try. Next, look for an accessory power relay, get a Haynes or Clymer manual, and see if swapping that out helps. After that, start wiggling the wiring harness to see if you can cause the problem. Try to figure out which connector is the problem and clean it. You might want to try to wire wiggling before the relay replacement.

Finally, it could be the radio itself. Replacements from Crutchfield are inexpensive and they give you the adapter wiring harness and any mounting kits if you buy a replacement from them.