CDR 220 Problem

[ivygreen]

On my '99 cab...

The problem started slowly. Every once in a while when I put the top down, the radio would shut off. After a while, it would power itself back on. Now, the radio will almost never power on at all. During a recent road trip however, I was driving at night. With the headlights and air-conditioner on, the radio would come on...sometimes If I turned the air conditioner compressor off, however, the radio would go out. It didn't happen every time, but I figured that it must have something to do with electrical load - like the radio likes less current, more load. Has anyone else experienced this? Does anyone know what the fix is?

[MattKellett]

Well I don't have a '99 cab........

But, a similar thing happened with my '87 when the voltage regulator/ alternator went bad. First my radio shut off and then the car quit on me and failed to start. After I replaced the alternator everything worked fine again.

I'm sure someone will correct me, but I think a quick way to test if voltage regulator or alternator have gone bad is to check the voltage at your battery while the car is running. I believe it should read about 12.5-13v, but again someone with better skills than me will probably give you a better idea.

Good luck anyway.

[NoEardGoat]

Battery should read 12.5-13v with car not running. With engine running and rpms above 3k you should see more than 14v at the battery. If you see less volts than with the car running that not running then your charging system is drawing from the battery a definite sign it isn't charging. This is standard for any 12v engine. I am not particularly familiar with Porsche charging system so I can't get very specific on where to go from there, but usually check for loose battery cables, voltage regulator, then alternator. Someone correct me if I am wrong.

[ivygreen]

I haven't checked back here for several days. Thanks for the responses. I'll check the charging system.

My wife drove the car the other day. She turned the defroster on and the radio worked fine for the rest of her trip. Maybe the car just hates me...

[SteveTeo]

I just bought a beautiful '99 Boxter with the same problem. Seems that the electrical load or charge on battery may affect many functions. Sometimes I can't operate the top unless car is stopped and handbrake engaged. My radio only runs when car is not running, with key in accessories mode (on). I'm going to have my voltage regulator and battery checked/replaced and let you know if that fixes the problems.
Steve