Electric Aerial Problem Possible Relay?

[Galee]

Hi I have a problem with the electric aerial on my mk 3. When I got it the aerial did not go down and made a wearrrring noise. Done plenty of these on mk 2s so order a new mask fitted it last week all fine and danndy until today. When I started the car this morning I could here the plastic teeth of the mast meshing agaist the cogs inside the motor. I striped it down and checked everything and all looked good. It seems that the relay is staying open for to long making the motor run more than it should.
So I timed the relay time when ign on and radio on without the mask in the motor it was roughly 15 secs and the same when ign and radio off. So inserted the mask back into the motor screwed the cap on then rechecked same again going up took 5 secs to get the mask up then run on for another 10 sec grinding the plastic teeth and cog. so switched off and it took 5 secs for it to retract the aerial and cut off but it does not run on when retracting. I have stripped the rear panel behind the drivers seat and found the auto aerial relay(85914-17010) but do not know how to test this.
It seem like this is sticking in the up postion for longer than it should. What I need to know is how does the relay know when to stop pulling in or pushing out the aerial mask? Anyone with any ideas? Also could a mk 2 auto aerial relay be used? They are diffrent part nos but they look nearly the same

[greglebon]

Does the aerial go up ok but not down?

When its retracting, give it a push to start it off: does it then retract properly?

If it retracts fully, then it MAY be that the nylon cord has detached itself from the top section of the aerial......

This typically has (in my experience) occurred with the Ebay replacements, as they dont seem to be attached firmly....

It has a crimped "cup" about 12mm deep to hold the cord onto the section.
As this takes a beating everytime the aerial retracts, it can pull loose over a short period of time.
This, I suspect, is NOT the case with OEM Toyota ones.....?

The retract action is goverened by the current draw of the motor (as is the lift).
When the aerial is fully down and cannot go any further, the load on the motor increases, and the relay turns off: same when it lifts.
So, if you have removed the aerial telescopic bits, and you turn your stereo on, the motor should, in theory, just carry on turning, trying to extend the non-existant aerial...!

I have, in the past, actually removed the thinnest section and transplanted the new one into the old OEM unit (not recommended, and a RIGHT PITA! )
More recently (today, in fact!! ), I have cleaned out the crimped "cup" with solvent, cleaned and keyed the end of the nylon, and epoxied it back in place......

Whether this actually holds out remains to be seen...but I'll let you know, either way...!

The other problem as you well know is the white nylon snaps half way down....
This is typically due to the 10-year-old OEM nylon going brittle: most simply buy an (inferior) Ebay replacement and just feed it in during the retract cycle, but I can't help worrying about what the remaining snapped part is doing, as it is still wrapped round the cog...!?

It could, over time, foul on the new one that is wrapped round / over / under it, so increasing the load on the motor, eventually kidding the relay into thinking the aerial is fully up/ down....iyswim...?