Last update: after trying with up to 3 different relays, I read online about another common problem of these old Volvos that leads to a similar problem than mine: a defective antenna ring. I installed a new one 5 days ago and so far I haven't experienced the no-start problem again (knock on wood). S...

Radio + amplifier work without processor. Disconnect processor from radio and check. Yesterday I tried my 2 Dolby head units (SC-900 & SC-901) with both amps and I can confirm that the system does not work without the processor, at least not in my case. In fact, not even the central loudspeaker...

There are two boards; upon visual inspection I did not see any cracked solderings or burnt components, other than a weirdly-soldered ground terminal. Electronics are really not my thing so I can't say much more, I guess it could be repaired by replacing a couple of capacitors.

After checking for continuity on the cable loom and testing with a spare loudspeaker, I determined that the processor was to blame. Sadly I could not find a second hand processor for this system, so I decided to keep it simple and install a basic radio. Today I installed it on the car and finally I ...

I would suggest trying to find any cheap Volvo radio SC-805 or SC-815/6 models. Anything with an inbuilt amplifier. Does your car still have the original connectors undamaged for a radio without an amplifier? They are usually connected behind the radio and covered with foam to stop them rattling. I...

Small update: I got an SC-900 head unit and an amplifier from a scrapyard and I still only get sound from the loudspeaker on the dash. The small connector on the amplifier does not fit the (green) plug in my car, but it also has two pins, so I simply connected them using a pair of wires. I think it ...

Yesterday I received my "new" relay. When I went to replace it in the car, I noticed the one in use is not original: it looks the same, but does not have a Volvo logo. Upon visual inspection of the old one I could not see any cracked soldering, but difficult to see with the naked eye. I pl...

Thank you! An original relay from a scrapyard is on its way, but I'll try to get mine repaired to keep it as a spare.

wasn't there a way to resolder/fix them? I might be wrong, but someone of our regulars pipped one open and there was corrosion visible. The elements inside were regular electronic components that one could replace. From what I read in other threads the problem normally lays on the capacitors, and a...

Remember what I said that the SC900/901 has no internal amplifier. All other SC-XXX unit do. Over here they are pretty cheap to buy from junkyards, so maybe worth considering buying a 'test' radio like an SC-815/6 unit and see how that works as they have inbuilt amplifiers so you can test your radi...