I have what is probably the original radio in my 90 240. Radio is CR-712.Amplifier is HA-6115, 2X15W, "Smooth Clipping Circuit". 3 ohm paper speakers.

Both rear speakers work when I first start the car in the morning. Once it warms up, only the left rear works.

I have removed the two front speakers, hooked them to my home stereo and they work OK. The rear speakers are attached with rivetts and I have not removed them.

I put a voltmeter on the front speaker terminals and I get 5 volts when the radio is OFF.?? When the radio is turned ON, there is a one second delay and then the voltage drops slowly to 0 volts.??

Brickboard posts indicate that bad solder connections in the amplifier are the usual problem. Wiggling these wires at the amplifier does not seem to do anything, however.

Does anyone have a technique for locating and correcting these solder problems in an amplifier? I have not done this kind of work since my Heathkit days, many years ago, but I am willing to give it a shot. Or should I simply pull the amplifier and have a professional repair it? Or should I simply buy and install a whole new radio? Suggestions?

The color of the wires at the amplifier does NOT match what is in the Bently wiring diagram for an amplifier.