Antenna motor repair problem
 

A couple of months ago I bent my antenna in a car wash. The motor worked fine, but I needed a new mast. I even opened up the spool case to see that a plastic cord is what pushes the mast up and retracts it, and that little metal ball on the end of the cord gives the spool something to pull and push the cord by. Weeks ago, I went through a car wash again, and broke the anetenna mast completely. This week I finally bought a nonfunctional antenna assembly from a junk yard to salvage the mast from. Apparently, the motor was bad on it, because it wouldn't do anything when plugged in. That was OK, because the motor on my antenna was fine.

So oblivious to the How-To for mast replacement, I opened the spool case on my original antenna again, and noticed that I couldn't pull the cord out, because the ball's diameter was bigger than that of the hole the chord exited through. It seemed to me that I would have to cut off the end of the cord with the ball on it, but I wasn't willing to do that, because I wouldn't be able to reattach the ball.

It then occurred to me that if the mast isn't removable, maybe the motor is! I could transfer my original antenna's motor to the "new" antenna assembly. So I removed the 2 screws holding the metal cylinder that I thought contained the entire motor, and pulled it off. Well, it turms out that I didn't remove the whole motor, I just took the motor apart!:eek: The metal cylinder only held part of the motor, the rest is in the plastic it connects to. a metal shaft with a spiral groove, like a drill, protrudes from the bottom of the metal cylinder and into the workings embedded in the plastic. Worse, sticking up from the plastic were 2 little metal rectangles on opposite sides that are connected to the plastic section by braided copper wires! There was nothing holding these rectangles in place! No brackets, slots, nothing! I tried puting it back together, but it didn't fit.

Today I found the How-to thread on the mast replacement, which makes my blunder even more regrettable! I didn't see anything to help me in repairing what I did to the motor. I tried to put the motor back together again, and this time it fit! Then, with inspiration from the How-to I transfered the mast (and everytning else from above the spool case) from the "new" antenna assembly to my original one.

But when I took it back to the car and plugged it in and started up the stereo, nothing happened! The mast did not retract. The motor and spool did not make any sounds. It appears that taking the motor apart does break it! something must be misalligned. Those freely "hanging" tiny regtangular blocks must not be in the right position. If anyone knows how to fix this or can point me to a How-To for antenna motor repair, please do.

I could always try taking the broken motor apart very carefully to see how everything should go back together. But if that motor isn't actually broken, I don't want to break it too.

Re: Antenna motor repair problem
 

It's been a while since I've had one of these apart, but those freely-hanging rectangular (carbon) blocks on woven copper wire are the "brushes" for the motor, and there should have been some small springs behind them that would push them out of their housings against a copper cylinder called a commutator on the motor shaft. In order for the motor to work, the brushes must be in contact with the commutator- The springs hold them in place as the brushes wear down. They're kind of a pain to align and push back into the housings while you push the motor winding and shaft down into place.

Chances are the little springs bounced off into a dark corner of whatever space you were working in- ask me how I know. Your parts motor still has them though. Be VERY careful and attentive if you decide to take that one apart too.

Re: Antenna motor repair problem
 

Thanks Dave!

Those springs are still in place! I thought it might be a possibility that those blocks might go against the springs since the springs aren't doing anything. They're just sitting there fully extended, but their ends aren't touching anything. One side of each block is concave, so that makes even more sense. I'll try fixing it again when I get home.

Re: Antenna motor repair problem
 

The spring should be pushing the brush against the shiny copper parts of the motor. The concave side of the brush will be against the motor, the flat side against the spring.

Re: Antenna motor repair problem
 

That's what I figured, Dave. It was a major pain, and I needed an extra set of hands, but it worked!! :):D:) Thank you both!