Trouble shoot power antenna

Parr · 07-26-2013, 03:06 PM

Does anyone know how the power antenna on a 1980 911sc is wired? Mine was working great, then I went under the dash to fix a bent ventilation unit cable. When I put things back together, the antenna didn't work anymore.

I've check the switch power wire from the head unit, and it is still hooked up. I took it apart and reconnected it with no luck. I also tried to turn on the ignition and and make the switch connection, but I couldn't get any current.

Is there a connection that goes from the ignition switch to the antenna that I messed up when I was solving my ventilation cable issue? Does anyone have a general idea of where the connections to the power antenna are made? What's a good way to test the antenna motor?

Joe Bob · Joe Bob's Garage

They work when the ignition and radio are on. Power goes to the antenna and it raises up. Power off, it drops down. Some radios have a inline or unit mounted fuse.

Bob Kontak · Bob Kontak's Garage

Quote:

Originally Posted by Joe Bob

They work when the ignition and radio are on. Power goes to the antenna and it raises up. Power off, it drops down. Some radios have a inline or unit mounted fuse.

What the dancing banana is saying is to check that you did not bump the antenna cable that goes into the back of your radio. If is is retracted from the recess, it does not know when the radio is on or off.

If that connection is viable, look for inline fuses as he says. If that fails I will get you an electrical diagram from the tech info center. You can try it yourself. Use the 1982 SC diagram set.

RSBob · RSBob's Garage

If you have a red and green wire coming off the antenna, the red wire connects to all the time power - typically another red wire - and add a 3 amp fuse. The green wire attaches to one of the power leads coming from the back of the radio.

Parr · 07-27-2013, 02:45 PM

RSBob, do you know how the antenna is grounded?

I'll check for the red and green wires. I've checked the antenna connector. It is plugged into the radio properly, and I do get some stations still, the antenna just doesn't go up. I'm wondering if the antenna isn't grounded anymore. I'll check that it has all time power as well.

Just so I'm clear, the antenna gets all the time power so it can retract when you turn the car off, right? It also gets switch power from the stereo when the stereo turns on, correct? Is the all time power, which may or may not have an inline fuse, be connected near the ignition, or does it go through the trunk straight to the fuse panel?

Parr · 08-02-2013, 03:02 PM

Here's a pic of the antenna under the fender. There is a lose connection there. Could this be my problem, and where does it go? I don't see where it might have disconnected from the antenna assembly.

RSBob · RSBob's Garage

Yes there are there two ways which it may ground depending on the unit. The first is by taking the black wire coming from the base of the antenna and attaching it by an nut and bolt to the metal brace which secures the antenna from movement. The second is taking the same black wire and feeding it through the fender inside the car and mounting it to an established ground - or the hack method is scraping some paint off, drilling a small hole and securing the black wire with an O connector at the end using a sheet metal screw.

Parr · 08-02-2013, 06:01 PM

Rsbob,

Do you know What that loose black wire with the metal piece is for? Could it be my issue?

Joe Bob · Joe Bob's Garage

Put a meter on it....power and cycle the radio and ignition. No juice....it's a ground.

RSBob · RSBob's Garage

The loose black wire needs to be attached to the metal piece with the holes in it, IF the metal piece is securely attached to the body. if it is not attached, reattach it. Make sure the when you secure the black wire to the metal it is free of grime. You may want to sand it a bit. I bet that is your issue. No ground, no place for the electrons to flow.