ceweaver

I'm trying to figure out why my radio/cd player isn't working in my 79. Bubba had done some work back in the day to install a cd player back in the mid-late 90's, so I'm had a hard time trying to figure out whats going on. I think I've traced the problem back to the power antenna relay (under the parking brake console, just behind the parking brake handle). There are spots for two, 3 wire plugs on the relay. One is orange, yellow, black while the other is grey, green, white. I'm 99% sure the grey, green, white runs the power antenna (which actually isn't power at all- thanks bubba).

So the important one is the orange, yellow, black. The orange wire comes from under the driver dash and supplies the 12v of power. The black is obviously ground. My voltmeter shows this. The yellow wire then runs up to the radio/cd and I assume powers it up, but no such luck. When plugged in, no power goes to the yellow.

Anyone seen this before or have any clue what I'm talking about? Am I safe assuming the relay is shot?

Thanks
Chuck

Wuttin

Yellow Wire should be the trigger to shut the relay and supply power to the antenna when the radio is powered up. Don't assume the realy is shot. The yellow wire runs from the harness to the radio, then from the radio to the relay. If you're radio is not equipped to trigger a power antenna the yellow wire isn't doing anything.

ceweaver

The way mine is set up it has the orange wire running from the harness to the relay and the yellow wire running from the relay to the radio.

The old radio died (or so I think), so I bought a new one hoping it would work. From the old radio, the line that was battery+ had an inline fuse. This line came from the yellow wire running out of the relay.

I've hooked up a few cd players in the past without any problems. There's a ground, a battery+, and an acc. Battery+ is so the cd player always has some power to retain its presets. The accessory supplies functioning power to the player when the ignition key is turned on.

I took the relay out of the box and all looks and functions as I'd expect.

I have no idea what's going on.

KapsSA

I take this as meaning that the power antenna that IS there just doesn't work? Try connecting that yellow going to the relay to a known hot lead (batt term. at fuse box or to the battery) and see if anything happens. If the radio connection doesn't supply power it's a radio problem. If the power antenna is original or even a "service replacement" it probably just doesn't work. These antennas don't seem to have a long life, I've had to repair every power antenna in every Corvette I've ever owned. The nylon leader that pushes it up and down breaks from drying out(picture an uncooked spaghetti noodle ) Sometimes the internal contacts are in a position that you can hear the motor run, sometimes not.

ceweaver

The power antenna was replaced before I got the car with a non power antenna. Its always up.

KapsSA

Re-rereading your posts you're trying to get the RADIO to work? The orange wire has nothing to do with powering the radio. Look for a yellow wire coming from the fusebox area or run your own wire to the fuse box to a ign. terminal. If you are trying to find power FROM the yellow coming FROM the antenna relay you won't find it. Look at the diagram above, the yellow goes from the fuse panel to the (factory) radio where it is switched on and off inside and then comes out and goes to the relay. If your original harness is cut, look for TWO yellows, a black and a gray(light in radio). Follow the yellows, you want the one going towards the fuse box. You probably need to run a constant hot for the new radio memory, go to the fuse box "batt" term. Some guys take that power from the cigarette lighter, tho.

ceweaver

Didn't know there was a diagram posted (from work its blocked so not even a red X shows up). I'm pretty sure my lighter is cut, so I could steal from that as I don't need it. But then come the questions of where does the acc wire hook to (from the radio) and what is the purpose of the orange wire that is feeding 12v to the relay?

And most importantly, how did all this work before I attempted to change the radio?

I appreciate the help.

KapsSA

Then ignore any wires coming from the antenna relay, they have nothing to do with the radio.
I'd just start from scratch.
Battery+ to the fuse box "batt", Accessory to the fuse box "ign", and ground to a good ground. I'd add an inline fuse to both hot leads.

KapsSA

The orange wire is a direct hot lead to the antenna relay, always hot waiting for the yellow wire to trigger it.
I guess if you wanted to you could cut the orange and use it for your "battery +"(memory) lead. You wouldn't want to use it for the "accessory"(radio on) because it's always hot.(unless you want to listen to the radio with the key out of the ignition)

KapsSA

KapsSA

This is the yellow wire coming FROM the relay? Won't work, not hot from the relay, correctly wired is hot GOING to the relay when triggered. Find the other yellow under the dash.

L8279

You did check the fuse in the fuse box?