Hi All,

My 93 Volvo 940 still has the stock radio in place with the power antenna. When I first bought the car I removed it and cleaned all the controls with contact cleaner and it restored sound to all the speakers. I do however have two issues I'd like to try to resolve if possible - noise when lights are on and poor FM reception. I realize I can replace this with an aftermarket unit, but that is not the advice I'm looking for.

For whatever reason, whenever the car lights are first turned on, the radio emits a loud humming noise. This noise gets weaker as the car warms up, eventually disappearing altogether. I've already checked and replaced all the light bulbs to rule that out. Has anyone else experienced this problem? I briefly popped in a Pioneer headunit I had on the shelf and the problem is not present with this radio, only the stock CR-814.

My other issue is seemingly poor FM reception. Even local stations have static at times, and I cannot pickup rimshot signals whatsoever, even though they lock stereo in my 05 Subaru in the same area. I checked the wiring from the back of the unit to the antenna and everything is in-tact.

Has anyone experienced any of these issues? I figured I'd start by pulling the headunit and looking for any cracked solder joints, maybe just go ahead and reflow anything that looks suspect. Is there any known trouble components on the radio circuit boards, or other areas outside of the headunit I should look into?

 

Hate to tell you this but it's shot. I also have a 93 Turbo and have been through 6 - CR814's. Same problems, humming(thought it was the separate amp but it wasn't), static, poor reception, etc. I thought I was lucky with my last one. Everything worked great and then the FM reception dropped down to a whisper. 10 minutes later it snapped out of it and was loud and clear. 10 minutes later, same thing. I had one that started humming and thumping so loud it blew out a speaker(why I thought it was the amp shorting out). Something in those radios was fried. I don't know if there's any companies that can rebuild classic radios?

 

I'm certain it can be fixed, just wondering if it's worth my effort. I've recapped and performed other repairs on numerous home audio receivers/amplifiers before, just a matter of figuring out what is bad. Based upon lack of replies, guessing most people just swap in an aftermarket unit.
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In my case, the FM reception seems ok, it's the volume that is very low when it first turns on. After about 10 minutes, it's like someone threw a switch and it's perfect. If I switch to AM(which is always fine) the FM drops to a whisper again until another 10 minutes go by. Then it's normal again. It's that first connection to FM that fails. Then it warms up and works. I did try cleaning the band selector switch with contact cleaner but that didn't help. Side note - the early 90's cars we're known for lots of static(especially in AM) so they updated it later by adding a ground wire from the antenna to the body.

 

Are you still working on the radio? I have a 91 780 with a CR814 that works like a charm my problem is the antenna is a cheap Chinese replacement that takes of at quit an angle. I have a new OEM but none of the wiring from the front of the car is right. The dash switch is dead and there is no power to the rear. I can not find any prints for a 91 780 as it is different from all the rest of the 780s. I think it is the same as the 940/960 but I'm have a hard time finding prints for it.

 

For the time being, I ended up swapping in an aftermarket deck. I lost the two dash speakers working with the factory radio and said screw it. I still have it and hope to get it going again some day.

 

I don't know if you are aware of the make, if not it is made by Alpine. I have owned probably a dozen Volvos over the years, none of them had a good stereo.

 

I found this on one of the Volvo sites, it has all the service manuals on it, they are in Adobe Flash so you have to down load Ruffle and add it as an extension to your Browser. For some reason it does not want to copy the whole address. I'll type it in. http://www.volvotips.com/service-man...ir-manual.html

 

I found this on one of the Volvo sites, it has all the service manuals on it, they are in Adobe Flash so you have to down load Ruffle and add it as an extension to your Browser. For some reason it does not want to copy the whole address. I'll type it in. volvotips volvo 760 780 wiring diagrams service repair manual. Doesn't matter, you'll have to search a bit but all the prints are there.

 

I have a 780 with a CR814 that works good as you can get out of a Volvo radio, I've have many Volvo's and all the stereos are the same, poor. As for the static, do you have the ferret iron ring on the antenna cable? Don't know if it will help but can't hurt.

 

Does the radio happen to get good reception on AM radio by chance? If so, you may be getting some radio frequency interference. My old truck has a suppressor mounted near the coil from the factory just for this reason. You should have a relay under the hood, driver (left) side, mounted just before the fender well.
Here is a link.
https://www.turbobricks.com/forums/s...d.php?t=307561