Factory Radio Repair

[Wes]

Does anyone know of a source to repair a factory 24v AM radio? Mine works, but the sound becomes very muffled and distorted when I turn up the volume. I have tried two different speakers (1 factory and 1 aftermarket), and they both sound the same. At about half volume, the sound is much clearer, but not as good as it should be.

The tuner also sticks when I use the preset buttons. In order to get the tuner to move again, I have to free the mechanism inside the radio by hand. Either the spring has become too weak, or it is hanging up somewhere.

The light also doesn't work, and I cant figure out why. I took the bulb out and tested it and it works fine. Used my multi-meter to make sure I am getting power to the socket and I am. Install the bulb and nothing.

 

[RustyRanger]

The distortion at high volume is mostly normal, at least in my experience with older car radios. The internal amps send out a dirty signal when they start pushing them, you can also only drive a paper cone speaker so hard before it distorts.

 

[Wes]

The distortion is definitely not coming from the speaker being pushed too hard. I tested it with a decent aftermarket speaker that will handle about 50 times the wattage the factory radio can produce. If it is normal for the amp to start distorting like that I will be disappointing. I went through the effort to find a factory speaker to make the audio system original. It's really not usable as is.

 

[fhawk5]

I used these people to repaid a radio. The components on these are really old now and were never made to todays quality. Take a look.

http://carradio.com/

 

[RustyRanger]

The distortion is definitely not coming from the speaker being pushed too hard. I tested it with a decent aftermarket speaker that will handle about 50 times the wattage the factory radio can produce. If it is normal for the amp to start distorting like that I will be disappointing. I went through the effort to find a factory speaker to make the audio system original. It's really not usable as is.

Is this the first old Am radio you have used?

I heard a few in old pickups, and they all sounded bad cranked up much over half volume. Now, bad may be subjective, because I'm used to modern audio stuff. The OE AM radio in my dodge is terrible much over half volume, it might be considered great by others, but it's subjective, ya know.

Most of these older head units only have sub-10w output, while a more modern type will have 15-20 rms watts out. They will drive the speaker to a higher volume, without getting into the zone that they start to distort.The old stuff gets there much quicker, because the components are more limited, and thus they distort at a lower volume. The speaker can be as good as any and rated to honest 250watts RMS and it wont matter much because the signal is just as dirty.

Also the older components are now probably out of spec due to age ( and were usually lower tolerance to begin with) and that doesn't help things any.

It's like trying to drag race a F engine, it's going to make horrible sounds once you get it wound up out of it's happy place.

 

[Wes]

It is the first old AM car radio I have used. I'm pretty proficient with modern audio equipment, but not anything old. Maybe I'm just expecting too much.

 

[thecrazygreek]

You are... just enjoy the 5 stations and half volume. Why are the best stations on my fj40 radio playing Mexican music? The other are rush limbo and a hippy Jesus station.

 

[MoCoNative]

I was all happy about finding an old AM/FM radio from an early Toyota pickup that fit the dash hole and the factory AM faceplate fits it. Hooked it up to two 6" speakers set in custom wood boxes. It is totally inadequate, I was very disappointed. Down the highway it does not distort too badly on the FM channels, but it just cannot put out enough sound and becomes drowned out. Years prior I had a Kenwwod deck with 40 watts RMS, it was the most powerful I could find in the late 90's, it had beautiful sound through the same speakers. I had to have it pretty loud on the highway, but you could still hear well. Also the manual tuner just can't hold a station. I don't know if it is physically vibrating off the spot that much, or if it just can't pull in the stations around here depending on location, but I have to constantly try to adjust if tiny degrees to tune the static back out while bouncing down the road.

Yes very disappointed in my nearly stock radio replacement choice. I'm looking at retrosound and the like, but I'm not impressed with their low RMS numbers or price.

 

[RustyRanger]

The tuning problem is probably due to "drift", the older analog electronics have a hard time holding specific values as they heat up/cool down. A capacitor or resister will change in value, thus causing the tuned signal to "drift" away.

I've got a few old 60's transistor car radios,I hooked up to test out and they do it horribly over time. Tuning them is a art.

If you find someone who has the schematics for your radio, they may be able to replace the problem components, but I doubt it would be cheap.

 

[ginmtb]

You could always install the AM radio for that old time look and put a current Bluetooth enabled head unit in a Tuffy console...

 

[gcrump01]

Classic Car Radio Repair - We Offer FM Conversions

there are several places like the one above that can put modern components into a vintage radio. Same old look, new sound.

 

[Landpimp]

Bad caps most likely.

You can use some contact cleaner to help get the dials moving and the contact, pots, cleaned up. I use Deoxit for my old hi fi gear. If you have a local vintage hi fi shop that works on 60-70 gear, the tech can get it working again. I have a ton of old tube and solid state gear, some take nothing more than a good cleaning...others need more love.

 

[Wes]

@tomcrusr has previously posted that he installed the Pioneer MVHX-560BT in his stock location without cutting the dash by not using the standard housing the radio came with. I may give it a try. In addition to the stock radio, I also have the Pyle PLR14MPF which fits in the stock dash opening. Unfortunately, it lives up to its name. It is definitely a pile; dead spots in the volume control, USB doesn't work with iPhone, tuner is crap, etc. I only paid $17 for it though, so I guess I can't complain. It does look at home in the dash though.

I'll just keep the original radio in case I ever want to make everything stock again.

 

[Fast Eddy]

My old AM works, I think, as new, but I don't think I couldn't turn it up much over half without it sounding like sh*t. It's good for ballgames while working on it, and traffic reports while stopped at a light, but it's not loud enough to listen to while driving, really.

 

[TheHardWay]

I use Deoxit for my old hi fi gear.

Second that. A spraycan of Deoxit saved my old Kenwood receiver. I've used it on another Kenwood and a Marantz unit. Stuff is great!

 

[Coolerman]

Whats AM?

 

[Wes]

I ordered a can of Deoxit. We'll see if it makes a difference.

 

[mstakacs]

I have the original AM radio and prefer it over my JBL marine bluetooth with Polk home speakers attached to the roll bar powered by a 1600 watt amp (for my 16-year-old). I get one talk radio, one sports, and one black/gospel being pushed through the speaker under the glove box with another piggy-backed and placed next to parking brake held in place by its magnet. If I am tooling around in a 1977 tin can, I expect to hear static and the occasional base hit from the Cincinnati Reds. There's nothing like the top and doors off in the summer listening to baseball and can barely make out what the announcer is saying. I'm weird, I know.

 

[Wes]

I received the can of Deoxit today. A couple of shots into the volume mechanism and the area causing the tuner to stick, and the radio seems as good as new now. I was actually impressed at the volume the factory speaker can handle. I still haven't fixed the light yet, but I think I've narrowed it down to a bad bulb. It isn't blown, but seems to have some sort of intermittent problem. I'll get a new one and try it out. Thanks for the tip!

 

[Weber Sarge]

Big thanks to @Landpimp for knocking the cobwebs loose - got a couple of cans of Deoxit , one being the 100% flavor . I had used this stuff many years ago but could not for the life of me remember the brand name - drove me nuts as I've got some older hi-fi gear that could use a tune-up . I had already tried 3 different brands to no avail - got the Deoxit in yesterday so I'm stoked to get them fixed and back in service .
Sarge