[Mk2] [Generic] Weird buzzing from back of car with ignition off - aerial no longer working

[rev3gtturbo]

I opened my garage door this afternoon to find my car buzzing. Sound coming from the rear.

No idea how long it had been buzzing for as it wasnt doing it when I locked it up in there about 18 hours earlier with all the electrics turned off.

I unlocked it and put key in ignition to see if there was enough juice in the battery to start the engine. As soon as I put the key in, the buzzing stopped. Not sure if it stopped buzzing as the key went in or as the key was turned through the first position. I took the key out and the buzzing had gone. Engine started ok. Been for a drive and no reoccurrence of the buzzing.

Since the buzzing incident the aerial has stopped working and is now always retracted.
All other electrics work still work.

I routinely turn off all electrics before turning off the engine so I am guessing the buzzing was the aerial motor or whatever controls it somehow getting confused.

I have had a look around the aerial unit and everything seems securely connected.

Only had this car a few months so dont really have much history for the electrics other than all the electrics have been working and I had a Clifford alarm replaced with an immobiliser, and I get intermittent echo type distortion through the speakers (playing cd and just the radio) which I was going to get sorted out in January.

As all the other electrics are working I assume the fuses are ok.
Is it simply the aerial unit has malfunctioned and died, or something else?

Thanks

[gavsdavs]

I opened my garage door this afternoon to find my car buzzing. Sound coming from the rear.

No idea how long it had been buzzing for as it wasnt doing it when I locked it up in there about 18 hours earlier with all the electrics turned off.

I unlocked it and put key in ignition to see if there was enough juice in the battery to start the engine. As soon as I put the key in, the buzzing stopped. Not sure if it stopped buzzing as the key went in or as the key was turned through the first position. I took the key out and the buzzing had gone. Engine started ok. Been for a drive and no reoccurrence of the buzzing.

Since the buzzing incident the aerial has stopped working and is now always retracted.
All other electrics work still work.

I routinely turn off all electrics before turning off the engine so I am guessing the buzzing was the aerial motor or whatever controls it somehow getting confused.

I have had a look around the aerial unit and everything seems securely connected.

Only had this car a few months so dont really have much history for the electrics other than all the electrics have been working and I had a Clifford alarm replaced with an immobiliser, and I get intermittent echo type distortion through the speakers (playing cd and just the radio) which I was going to get sorted out in January.

As all the other electrics are working I assume the fuses are ok.
Is it simply the aerial unit has malfunctioned and died, or something else?

Thanks

The chances are the aerial has stiffened up and the worm gear can't move it.

You probably want one of these.
http://www.ebay.co.uk/itm/SALE-AERIAL-M ... 19e69c34e4

It's a bit of a messy job but not too hard.

This guide is good
http://www.imoc.co.uk/technical/howto/M ... Aerial.pdf

[rev3gtturbo]

Thanks for the reply. I will have a look at the links.

Just to clarify the problem. The aerial had been working normally - fully extends and fully retracts. The radio was off and aerial fully retracted before the car went into the garage so the aerial should not have been trying to go up or down.

[gavsdavs]

Thanks for the reply. I will have a look at the links.

Just to clarify the problem. The aerial had been working normally - fully extends and fully retracts. The radio was off and aerial fully retracted before the car went into the garage so the aerial should not have been trying to go up or down.

Depending on how yours is wired up.....

If you turn on the radio the drive tries to raise the aerial. If it doesn't work, you get a grindy noise from the motor whilst it tries to raise it. Same when you power off your radio, the motor tries to drag it down. If neither of those is happening (you don't get any noise) - sounds like an electrical fault, not a mechanical one.

Best of luck.

[rev3gtturbo]

I would normally start the engine.... then turn radio on which would raise the aerial.... then eventually I would turn radio off which woud lower the aerial, then I would turn the engine off.

Since the buzzing incident, there is no noise at all from the aerial motor when turn the radio on or off.

The buzzing incident only stopped when I put the key in the ignition and turned it, suggesting something electrical happened to stop the buzzing...
dont yet know if its the motor, the control relay, or something harder to get at such as a short circuit.

I have two MR2s so once the storms have gone I can temporarily swap the aerial assemblies over and see what happens in both cars.

[rev3gtturbo]

The buzzing is the aerial motor. Can feel the vibration and the heat in the motor.

Tonight the buzzing started when I turned the ignition off and stopped when turn the ignition to the position that lights up all the dash warning lights etc. This seems repeatable (for now) so it might be easier to diagnose and fix.

I had a spare 5mins to rummage around the aerial unit and nearby wiring and could not wiggle anything specific that would stop or start the buzzing. I did try to move something that did make it stop once briefly but that was not repeatable and I wasnt sure what it was.

In the end I pulled the Dome fuse to stop it.

[rev3gtturbo]

Finally got around to trying each aerial in the other car.

The problem moved with the aerial so that aerial assembly will get replaced.

Trying the good aerial in the other car didnt go according to plan. To save time I did not put the mast top through the hole in the bodywork and did not bolt the assembly to the chassis. I just connected up the loom and maybe the mast audio plug. When I turned the radio on I could hear the mast going up in the boot space as expected. I went to the boot to make sure it was not going to hit the boot interior. Unfortunately it kept going until it the whole of the coiled cogged plastic cable came out of the assembly.

Do these aerials really have to be almost vertical for the mechanism to work properly and stop erecting the aerial when it is fully up? The problem with the other aerial was it was fully retracted and the motor buzzeded of its own accord, so not the same fault.

I will rebuild this aerial and install it properly before trying it again.

[keiith9849]

Old thread, but MR2 Ben has replacement aerials very reasonably priced, with reasonably clear fitting instructions. Antenna/gear replacement for original aerials is strictly for people with time on their hands!