Hi

I'm trying to fix my radio

Has anyone go a wiring diagram that you could email to me

I have a radio wiring manual but it's for a 68 which is a different layout

Also anyone got any 'fixes' for these old radio

mine buzzes all the time with no radio signal present

many thanks

T

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'67 Dart 225 Super Six

I fixed the factory radios in all our TMC giveaway cars that still had the factory radio over the years (www.tidewatermoparclub.com).

I found Sams books of schematics and instructions at www.tannenbaum.com; I am very, very pleased with them. You'll need to know the exact model# of the radio; close isn't good enough. It should always be on a sticker on the case and obvious with the radio out.

Previously, I tried to track schematics down via Chrysler Corp. and Motorola (who made the radio for Chrysler) - neither would help at all, and I've since been told that Chrysler lost or discarded all their old records on them.

I generally don't bother to fix aftermarket radios - it just isn't worth the bother when you can buy another cheaply.

Let me start with general suggestions for dealing with 1960s factory radios and then get specific to your problem.

In general, I found that the speakers were always shot from old age, so check them 1st. If you connect a good speaker and get no sound at all, not even a thump when you turn it on, the next most likely thing is the power transistor.

You can replace that from the outside without soldering or even opening the case, but I would examine the insides first anyway for obvious damage. I've found reasonably close replacement power transistors at Radio Shack.

About 10-20% of the time, I've found that the impedence matching transformer is totally and obviously burned to a crisp. I've not found a source for replacement transformers.

Next, I'd start in on the electrolytic capacitors; old ones start leaking current internally and sometimes acid externally.

If the radio's transformer or board is fried or badly corroded, it might be easier to gut it and put in all new electronics, or purchase one from Custom Autosound; they're supposed to fit perfectly.

I've purchased a radio from Crutchfield that supposely fit my 1980 car; it came with a pretty good installation kit (the only one I'd ever seen for that car), but when things actually didn't quite fit their tech support guy just told me that he'd had the same problem and that they couldn't help at all.

In your specific case, I suspect that your power transistor and transformer are OK. I'd take it out of the car and open it up and look for problems before I did anything else.

If everything looks good inside, with a proper speaker load (typically either 8 or 16ohms; either would work well enough for testing), power, ground, and an decent attenna connected, I'd look at the DC biases with a DMM as shown in the Sams book. If one or more looks way, way off you probably have a shorted cap or a cracked resistor. If the biases look OK, you probably have a dead signal transistor.

You will probably find an exact transistor match hard or impossible to find, but these designs are pretty forgiving and most times anything even close will work. Often a 2N2222 (NPN)or 2N3904 (PNP) will work well enough for the IF stages.

Good Luck, K