| Lately, I have been having a problem with my antenna not rising or retracting reliably for a while. Sometimes it would work fine, going all the way up and all the way down as it should, but most of the time it would rise a couple inches at a time each time the radio was turned on, but then not retract when it was turned off. I could hear the motor try for a second or so, then stop. Eventually,after several on/off cycles of the radio, the antenna would be fully extended, but it would not retract. I could manually retract it by pushing it back in. This told me the cord wasn't broken. Then the cycle would start all over again when the radio was turned on again. Last week I switched out the antenna timer with a known good one to eliminate it as a possible culprit. Still had the same problem. This weekend I dismantled everything in the assembly - mast, gears, motor, everything. Then I went about troubleshooting each component. The mast cord was intact as I suspected. I cleaned it of gunk and relubed it. All the gear teeth were in good shape. All were cleaned and relubed. With the motor removed, all the gears turned as they should and wound up the mast cord. So then I took only the motor out to the car, plugged it in, and turned the radio on. The motor ran for a bit, about the time it would take to fully extend the mast, then shut off. But when I turned the radio off, the motor only ran for about a second before turning off. It would do this each time I tested it. Then after a while it would only run for a second or two when running in the "extend" direction, then an even shorter time in the "retract" direction. Basically there didn't seem to be any consistency with it. I pulled the top of the motor off to reveal the copper wiring and innards of the motor. I'm not an electronics guy so I really had no idea what I was looking at, but everything looked to be intact, with no obvious breakage of wire or loose looking things. It was a little dirty so I cleaned everything with electrical contact cleaner. Retested, and got the same result. So my question is, what exactly wears out in the motor to cause it to exhibit the behavior I described? If a pic of the inner motor would help let me know and I'll take one and post. Thanks for the input.
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