S40 Electric Aerial Motor Fault

[burgo]

Hi, my electric aerial motor keeps running and running whether the radio is on or off. I have had to disconnect the power.
I have removed the aerial and cleaned up and reattached mast, but can not seem to get the motor to function properly. It seems to make a noise but no turning takes place. I have spent the past 2 hours this evening trying to sort this and have now given up . Do i need to replace my motor, or am i doing something wrong ??
All help appreciated.

[Palladin]

I appreciate your problem cropped up some time ago. You may have found a solution by now. I have just experienced the same problem with the motor running continuously when the the aerial is retracted (radio or ignition switched off). I have previously replaced the telescopic aerial and nylon drive twice without a problem but this puzzles me. I am presently working on the unit on a bench to try and see why this is happening. The wiper contacts clearly have an important part in sensing when to switch the motor on or off and are visible but not yet sure what position they should be set at. I have verified that there are 3 feeds to the unit being earth, a permanent source of power +12v and a switched +12v from the radio. Also there seems to be a 'slip' arrangement on the big wheel that the nylon cord winds on so that if the nylon cord is fully wound on (aerial down) but the wiper contact has yet to reach its termination setting, the motor continues to drive, the big wheel slips and the contact wheel continues to drive until it reaches a pre-determined point. This point is when power is taken off the motor. That's the theory but not the answer. Any update is welcome.

[Palladin]

This is a follow up to my original reply as I seemed to be running out of space in my response. It does not provide a solution but has focussed my mind on how the thing works and might help others with same problem. Everything mechanical and electrical looks ok so the only thing left is the possibility that the unit has gone out of sequence with the control board (the printed circuit board that turns and is wiped by three contacts). I guess that this is the bit that determines when to shut off power to the motor when the aerial is fully retracted and when to switch on the power when the aerial is required to be raised. That's as best as I can say at this time. I am going to continue investigations with a hope that I can eventually fully understand how this unit functions. After which a repair should be .......................easy!.

[burgo]

Hi Palladin, i vaguely remember this, as i eventually found my problem to be the nylon "cogs" inside the unit that had several teeth missing causing my problem. I eventually found a brand new vauxhall aerial on eBay for £20 that was identical except the wired plug and so decided to take the inards out of my original one and replace with new (so being able to keep electrical sockets) and this seemed to have done the trick.
As i said at beginning of this reply, i vaguely remember the wiring and how it decides whether to send the aerial up or down but at present I am unable to offer any further help on this - sorry