Norsky said: Welcome to the world of funky electronics...!!! A regular AM/FM radio just had one of those components while a stereo AM/FM radio had two different ones. I'm not sure just what part they played in making music, but they were required.

My 75 has a steroe radio I'm pretty sure. It will play for maybe 3-10 minutes and then cut out. If you turn it off and back on it will play for another 30sec-10 minutes. Wash rinse repeat. Everytime you turn it off it plays for less time. Shutting down the car starts the process all over again. Could bad convectors be causing this?

Scot

Scot, I'm no electronics expert either, but it seems to me that the point of the convector is to disapate the heat. Maybe yours is heating up and cutting out?

I really don't know, it's just a guess. Since I don't have my original stereo I just don't know.
Glenn

Scot, I'm certainly not an expert either, but this guy (Gordon Ward) did a great job fixing mine, suggest you contact him. He will only work on the older radios, 1968-1976. E-Mail: glw@mchsi.com

The convectors ONLY purpose is to dissapate the heat generated by the transistor in the center. I have had the opportunity now to look at more pics of them and I can say, with some confidence, that the reason the stereo has two and the mono has one is that they are used for amplification of each channel. If someone has a wiring diagram for the radio i'd love to take a look at it so I can give you all a more thorough explanation of the purpose. However, all the convector does is dissipate heat.
This COULD cause your problem, however, since it is a completely passive component (It's just a hunk of metal, no electrons) I would doubt if it is the cause. The transistors in the center however are a different story. After time the older transistors would fail from heat stress. The heating and cooling process making them expand and shrink would eventually "cook" them. It should be a very simple fix if this is the case. Take the transistor off the convector, get the number, and get a new one.
This company should be able to get you any old obsolete component you need. www.aeri.com

The transistor should be "easy" to get and easy to hook up. It should have two or three wires going to it, labeled G,D,S or some other variation. Gate, Drain, Source. Most likely AC Delco part, if you can't get it at the website, you'd be surprised what your local Radio Shack can do for you.