I need to know the wiring of the radio wiring harness for my SC-816 radio in my '99 S70. Do you have or know where I can get this info? I am looking everywhere.

My problem is the signal for the ASC(automatic sound control) is apparently bringing lots of buzz into the radio (buzz goes away when I am stopped and I can hear it increase when I accelerate/decelerate). This occurs when listening to the AM band only, which is very susseptable to impluse noise of this sort. It is similar to alternator whine, but obviously it is tied to the speed of the vehicle thru some specific sensor. Turning off ASC has no effect. Buzz is there regardless on the AM band.

I intend to try disconnecting this speed input or at least putting a big capacitor on it or putting it thru a noise reducer type circuit normally used to clear out alternator whine.

-Mike

There were a couple of threads on the UK Volvo forum at http://www.volvoclub.org.uk/ which discussed colors for each of the wires for various radios. If you are handy with a voltmeter, you can probably figure out the wiring. You should have a ground (generally a black wire), a wire for the electric antenna (generally a blue wire), either 2 or three power supply lines (usually you can identify these wires because they will have an inline fuse; one line will be direct to the battery to maintain memory for frequencies and such, one will only have power when the ignition is on, and another will tied in with the lamp dimmer controls. The CD connections for my SC-813 had a seperate connector. The other wires will be for the speakers and possible the sensor you are looking for. Each speaker will have two wires (+) and (-) but the (-) wires may be shared between 2 speakers. I have used a 9-volt battery to confirm speaker connections. Just connect the battery between the two wires that you suspect are speaker wires, if you hear static on a particular speaker, then you have found the (+) and (-) connections for that speaker.

If it isn't alternator whine the noise could be generated at one or more of the wheels.
--
1999 S-70GLT, 22,500 miles, turbo replaced at 4,000

The car is not a GLT (turbo). The whine is tied to the vehicle movement while under engine power. I have turned off the engine while going downhill and the noise goes away. I have put the car in neutral while going down hill and let the RPM go to idle (It's a long hill), and the buzz remains tied to the vehicle speed, as it should for the ASC function of the radio.

Got a radio wiring diagram?

-Mike T.