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I bought a 77 Ford LTD, and the damn thing has immediately become a money pit. Engine's blown, and just about everything else is not working. Among which is the radio.

At first, it would do nothing at all. Except the speakers would pop when you turned off the radio. Out of the car, I'm messing with it, and I discover I can hear some radio station coming in if I hold the volume knob right at the on/off detent. I wash out the pots with contact cleaner and now the speakers work. I fixed a couple of suspect solder joints, with no effect. FM is stuck on one station with no effect from the tuner, and it comes in so poorly I can't make out what the DJ says is the station frequency. But they did say 'slow jams' which apparently is not a station that exists in Chicago. Also, the stereo indicator light seemed to come on and pulse with the more bass-y parts of the music.

I very carefully messed with some of the tiny adjustment pots on the board, making sure to put them back were they started, and one of them changed the tuning, and would pick up different stations.

On AM, it's only silence. Until you turn up the volume and it goes pop pop pop, and interestingly the pops get longer and less frequent the higher you turn the volume. Messing with the tuner will give that old timey squeal when you tune between two stations, but nothing actually comes in.

Unfortunately, all of the stickers have fallen off of the radio. I intend to fish around in the dashboard and see if I can find one. The big yellow sticker on the top was a quality control sticker that fell off when I removed the radio. All I have to go by is an ebay listing that looks just like it:
https://www.ebay.com/itm/35348241005...kAAOSw9nBgdwxh
Identical on the outside, except mine is not marked 'Aeronutronic.' Mine has a rubber stamped number on the side: 18812. There's a piece of masking tape on the bottom from a previous repair that reads:

Code:

G. BA??

10-16-77

RO# 56242

FLOAT

Interesting that it was repaired the same year the car was new. I'm wondering if it's not the original radio. Not sure, but the repair looked like just a couple of joints resoldered in the middle.

Any ideas?

Quote:

Originally Posted by MadMan (Post 3233661)

Code:

G. BA??

10-16-77

RO# 56242

FLOAT

It's made by Philco, the part numbers attest to that.
Check the salvage yards before they are all shredder fodder.

If you're interested in hiring it done, give this guy a holler - https://www.bing.com/search?q=bill+t...FORM=QBLH&sp=1

Quote:

Originally Posted by old_coot88 (Post 3233675)

If you're interested in hiring it done, give this guy a holler - https://www.bing.com/search?q=bill+t...FORM=QBLH&sp=1

The salvage yard is still a better idea!
Way back then, I had a Ford radio in for repair, about the same vintage, that had two component packs, one for each channel. One was bad, so I replaced both. They were made by Centralab and it was obvious that contained a transistor or two, plus other components.
Better to source another radio, instead of trying to get it repaired.

Quote:

Originally Posted by dieseljeep (Post 3233672)

It's made by Philco, the part numbers attest to that.
Check the salvage yards before they are all shredder fodder.

I've already been to all the junk yards in 100 mile radius, there's nothing that old anymore. Hell, there aren't even any 90s LeBarons anymore (my other old POS), finding a 1970s Ford would be like finding the holy grail.

Ok, I've made an improvement. Turns out one of the cover screws is needed to ground a section of the board. The one radio station now comes in better, enough for me to hear the DJ say it's 104.3. Tuner still does nothing. AM behaves mostly the same, except instead of the popping sound, it's just constant bass. Turning the volume down low enough eliminates the sound. Seems to have a threshold.

Wires for the antenna adjustment trimmer were reversed, but no effect on correcting it (one is grounded). All suspicious solder joints have been reflowed. The tuner board is connected via spring pins in holes, those were all cleaned.

What the heck would cause it to ignore the tuner and be stuck on one station? And also, is there any way I can get a Sam's for this, not knowing the model number?

I got the sams for model# D7AF-19A241BA. It seems correct.

Thinking this was a floating ground problem, I put the board back in the metal case. All I got was static after that on FM, silence on AM. Took it back out, manually hotwired all chassis ground points, and it's picking up the same station on FM. On the very top of the AM band, I get a whisper of a station. I've come to find out that it's receiving (the FM station at least) through the chassis ground. Hooking the antenna wire I've been using to chassis ground improves the signal.

I've ohmed all the tuning coils. None are open, but I think my meter is a little off, read most of them a bit high resistance. Replaced one electrolytic that feeds the input to the multiplex decoder IC - it looked funny - no difference.

Can someone please chime in and tell me what section I should be looking at?

>>Schematic<<

Replaced all electrolytics. I guess they didn't survive 44 years of baking in the Arizona heat. Works much better now, you can actually tune stations. AM kinda works, I don't care about AM, but also I don't have a real antenna for testing. Sound quality is kinda crap. Either it needs to be in the case for shielding, or a real antenna, or maybe something else is still out of whack.

I'm thinking of adding an aux port and injecting the audio at 35 and 36 right after the mpx decoder. Is it ok to leave the decoder's output floating?

I have one very similar to that one, out of a '78 LTD. Identical knobs, even the same wear pattern on the tuning knob. Mine has an 8-track player (needs belt) and is made by/for Motorola in Japan. The radio was working when it was removed from the car ~ 2000. If you're interested in it, send me a PM.

Hi,
In older shop manuals (40s/50s - GM, Ford, MOPAR) it was common to place the car radio schematic inside the electric division.
Because of all your trouble you can' t get around an original shop manual anyway.
It will be your best investment before you go on with the car. Hope they places radio schematics in the 70s.
Good luck!

TV-collector :stupid:

Actually, I bought the whole 1977 Ford shop manual set. The 'electrical' section is a joke. There are really no schematics in it, with the exception of the A/C. Fortunately, I had some vintage repair manual PDFs, and one of those had the basic whole car wiring diagram. So at least I have that.

At any rate, I found what seems to be the correct Sam's, so I'm good on that.