Identify radio pinouts with a multimeter?

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Damn,

94 Chevy C-1500 pickup. It's a basic WT (work truck) that came without any interior trim and with a basic mono AM radio. I went to the junkyard and grabbed a stereo am/fm but was only able to find pre 91 radios. Perfect drop in fit, but instead of two multipin plugs and a coax connector there is simply a two foot pigtail with a six pin plug at the end.

Seems strange that the antenna signal would be fed through one of these pins, but that must be the case. Is there a way to determine the power/antenna/grnd/pos speaker on this plug using a multimeter?

Thanks for any advice.
 
You said the radio that u grabbed from the junk yard has a 2' pigtal on it. Sounds like u grabbed the radio but not the tuner/amp that it nees to work there should be a tuner/amp within 2 ft of the radio somewhere in the dash of the vechile u grabbed this radio from. Thats what im thinking IMOP
 
I got the radio out of another similar, but older truck. It's physically identical, but when I got home and actually removed my radio, it had two sections of pins on the back as well as a connection for the antenna coax. The one I got home from the junk yard simply had a 2' pigtail coming out of the back with a little six pin plug at the end.

I just spent an hour looking at pinout diagrams for different years and it's looking like I should just wait until I can find a direct replacement from my year at another junkyard. It's strictly for utility and I don't want to blow half of what the truck's worth putting a custom radio in. But the static and content of AM just raises my blood pressure.

I understand that the amp is separate from the radio in these units, but since the older radio has no co-ax connection, and the newer unit does, I wonder if the actual tuner section is somehow remote as well (strange setup). I found generic color codes for GMC radio wiring, and that would probably do me, but the antenna/tuner business worries me.

Just can't find any junked trucks newer than '92 locally. Any places you know of in GR that stock a roomful of car radio take-offs? I'm in Grand Haven and am generally there once a week.
 
bluebeard said:


I understand that the amp is separate from the radio in these units, but since the older radio has no co-ax connection, and the newer unit does, I wonder if the actual tuner section is somehow remote as well (strange setup). I found generic color codes for GMC radio wiring, and that would probably do me, but the antenna/tuner business worries me.



Yes, it was a two or even three piece system. The control unit was a very small, non-standard size mounted in-dash. The cassette deck mounted to the right of the instrument cluster, nearly in front of a center passenger.

The external tuner/amp was mounted under dash below the control unit. If you lay on your back in the floorboard with your head nearly against the gas pedal, the tuner/amp will be above your chin. It's not hidden behind anything, but IIRC there is a mounting nut on the top that's difficult to reach.

Power, speaker, and antenna connections are on the amp, as well as an input for the cassette deck. I used the cassette deck input to add external CD players back then.

You may want to go back to the junkyard. I'd bet that they have a truck with this external unit still in place. Tell 'em it should have come with the radio you bought...
 
Do you happen to know if it is simply a matter of finding the correct year? I already returned the radio to the yard for a refund. If a newer model (the radio was a '91 and my truck is a '94) am/fm will simply plug right into the existing plugs now dangling out of my dash, it would be much simpler than trying to fit the older style box under the dash. It may even be that in '94 they quit using this arragement and I can no longer simply bolt it into the space.
 
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