[Mk2] [Turbo] Aerial not stopping at full mast

[rob6539]

Hi guys.

My aerial is extending in full and going back down as it should. However when it extends the motor doesn’t stop and you can hear the gears jumping and dancing around inside.

The aerial used to work, after I replaced the mast; however I have needed to fiddle around with the stereo wiring since then...?

Any ideas why the aerial might not be stopping at the top?

Broken relay? Broken aerial gear? Incorrect stereo wiring feeding the aerial? Or something I haven’t thought of?

Any help would be very much appreciated

[toecutter]

This may be of use.

http://www.imoc.co.uk/technical/howto/M ... Aerial.pdf

[rob6539]

Hi mate, thanks for the response.

I'd seen that pdf before, whilst trying to consult google for assistance. Unless I'm missing something from the text, I can't see why my aerial wants to keep scrolling up until it pops out

Unless it's the ANT signal is not switching off? If so, do you reckon this is an issue with the wiring from the head unit, or the relay?

Thank again

[toecutter]

Suppose it could be that, could check if the ANT is constantly live?

Could also be something broken in side if its trying to move it up when it can't go any further.

[gavsdavs]

The motor is driving a semi rigid nylon rod with teeth on it by means of a worm gear and a clutch.
This coils up inside the assembly when down and pushes the aerial up when powered on.
The nylon rod has probably broken and the bottom bit is stuck inside the assembly, the top bit is still in the aerial.
The rod is being raised until there is no more rod to raise, with the bottom bit in the assembly.
The motor never hits the resistance of a fully extended aerial for the clutch/motor disable to take effect.

You need a new aerial assembly (make sure you buy the right one for your spoiler/boot as the rev1/2 are different to rev3/4/5 - assuming sw20).

It's a mucky job but not too hard.

You'll be amazed how tall the aerial is once done !
http://www.gavdav.demon.co.uk/Offside_rear.jpg

Edit - I just realised you have replaced the mast so you have opened it up.
Was it the right aerial ?
Does it fully extend (does the motor drive it to the top so you can't pull it any further).

Just makes me think there's something loose in the assembly jamming things.

[rob6539]

I'm pretty sure it's the correct aerial mast; but that's a good idea, I'll try connecting it back up and running the stereo till the mast stops and see if I can manually pull it any longer.

So does the motor know when to stop extending from resistance? I'm been scratching my head trying to work out when it decides it should stop turning?

[Odin_S]

I had this problem a while ago on my other MR2 it turned out to be the mast. Try that first as it's the cheapest.

[gavsdavs]

So does the motor know when to stop extending from resistance? I'm been scratching my head trying to work out when it decides it should stop turning?

Yes I think it does, (that's the behaviour I see) but don't quote me on that.
Did you crack open the case to remove the old mast debris or just replace the mast.
You will have noticed that the nylon flexible rod wll have been longer on the new one, the end of the old bit still being in the casing.

[rob6539]

Yeah I opened up the casing, there wasn't much left in terms of the old nylon mast flexible rod.

[gavsdavs]

I guess i was relatively lucky - i managed to fit it right first time - it drew in the extended aerial when i turn on the radio, and it now stops the motor correctly when fully down and fully up.
Best of luck..

[rob6539]

It was working beforehand when I first replaced the mast, but has since decided to be difficult. I'll try and have a look at it over the weekend.

Thanks for the pointers though

[rob6539]

Gonna re-ignite this thread if I may?

I've finally gotten round to looking at my dodgy aerial mast again.

As it stands, the aerial retracts perfectly, and goes up when activated. However, once the mast has reached to top of its length, you can still hear the motor turning away inside.

This lasts for about 15 seconds and then stops.

Any ideas what may be causing this to happen?

[Odin_S]

I would say maybe you damaged your new mast ( did that before on my old car) Or there istoo much crap on the gears

[rob6539]

I would say maybe you damaged your new mast ( did that before on my old car) Or there istoo much crap on the gears

Thanks, guess I'll to take all apart again and have a look.

I noticed today that when the mast was extended, from listening to the radio, I switched to listen to a CD and then back to the radio. When I switched back to the radio with the mast already extended the aerial motor started grinding again for the same 15secs.

Wondered if I've wired something up wrong and the stereo is sending an unwanted signal to the arterial?

[Odin_S]

I wouldn't think so, I've played with the whole aerial system on a SW20 for ages. I doubt the relay is at fault

[rev3gtturbo]

I would say maybe you damaged your new mast ( did that before on my old car) Or there istoo much crap on the gears

Thanks, guess I'll to take all apart again and have a look.

I noticed today that when the mast was extended, from listening to the radio, I switched to listen to a CD and then back to the radio. When I switched back to the radio with the mast already extended the aerial motor started grinding again for the same 15secs.

Wondered if I've wired something up wrong and the stereo is sending an unwanted signal to the arterial?

Could be wiring If you look in the Knowledge Base for the aerials the wiring diagram shows it can be wired so that the headunit can control whether the aerial is up or down.

When I bought my previous mr2, it had a jap double din head unit that would retract the aerial if you were listening to cd and raise the aerial when you changed to the radio. When that headunit eventually died, the new headunit always kept the aerial up for everything (maybe for the rds function?).

I liked the option of being able to listen to a non-radio source without the headunit trying to raise the aerial if it was frozen over in winter.

I was discussing aerials with an audio installer this year and he reckons its been years since headunits retracted the aerial if you decided to listen to a non-radio source.

[toecutter]

Did you ever get to the bottom of this?

I finally got round to sorting my aerial - it wasn't wired in and the mast rod was snapped.

Fixed the wiring and fitted a new mast (cleaned everything inside and used fresh grease).

When I tried it up and down it worked fine a couple of times, but now the motor runs on at the top for about 10 seconds.

When at the top it can't be pulled any further. Took it to bits again, the mast wasn't damaged at all.

Any ideas?