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As per topic subject, the antenna on the NB8A is supposed to retract when the radio is turned off or ignition turned off. Mine doesn't do this. Someone is selling his spare antenna elsewhere on this forum but I dont know if the problem is in the antenna motor or somewhere else. Can anyone provide me an IDIOT'S GUIDE to test this and what else the problem might be? I dont want to spend a heap for auto electrician to fix if its something as easy as changing over the antenna unit, esp at second hand price.

Sorry if this has been covered before, advise link if so.

Thanks.

CJ5 wrote:when you turn the car on/off do you hear a noise coming from the antennae motor?

No noise. I have a VY Commie with a retracting antenna so I know the motor noise from that.

Do you have the factory stereo in there?

If there's no noise at all then the motor may be stuffed. I have a feeling there's a fuse for it somewhere so I'd probably be checking/replacing that first.

I'm fairly sure there's a fuse. Have a look in the fuse box to see if anything's blown.

Another one worth checking is to see if the wiring loom/plug has come loose out of the antenna motor. You'll need to take out the carpet around where the antenna is, but that's not hard. You just need to remove a few "squid" clips and possibly the little plastic cubby hole to get the carpet out. Once you've taken out the carpet, the antenna and motor should be in plain view. There's a white plug that's supposed to go into it. If that's come loose, that's your problem.

marcusus wrote:I'm fairly sure there's a fuse. Have a look in the fuse box to see if anything's blown.

Another one worth checking is to see if the wiring loom/plug has come loose out of the antenna motor. You'll need to take out the carpet around where the antenna is, but that's not hard. You just need to remove a few "squid" clips and possibly the little plastic cubby hole to get the carpet out. Once you've taken out the carpet, the antenna and motor should be in plain view. There's a white plug that's supposed to go into it. If that's come loose, that's your problem.

Thanks Marcusus. The fuse is the same 10amp one the interior light and warning buzzers are on. They all work so its not the fuse.

Had a look at the bottom of the antenna assy: plug is in place with black, black/white, blue/red wires seem to be firmly in place. Nothing appears out of place there.

The stereo is standard with the six stacker cd in the boot from new.

Is there a way to test if the motor is burnt out? (haven't got a multimeter at home but can get hold of one).

Appreciate any more ideas...quick before Top Gear comes on!

There might be a short in the trigger wire which is causing it to stay raised? If you do get the multimeter, set it to read the resistance (the omega symbol aka ohms). Make sure the car is completely off (no accessory power). Connect one probe to one wire and the other probe to another. Repeat this for all combinations of wires so that you've essentially connected every wire to every other wire. There's only 3 combinations. If you get a reading that isn't infinity/overload/whatever (aka an actual number) then there's a short somewhere in the line, which means it'll be a real pain in the rear to fix.

This of course assumes that the radio itself doesn't do some sort of shorting across the cabling. I suppose I should just try it on my NB8A antenna and see what results I get (I know mine works, and I've currently got the carpet out).

Okay, I'll pick up the multimeter and try that tomorrow night. Fortunately it is stuck in the up position *insert viagra joke here* so could be left if too difficult to fix.

Quicksilver wrote:Okay, I'll pick up the multimeter and try that tomorrow night. Fortunately it is stuck in the up position *insert viagra joke here* so could be left if too difficult to fix.

I just went and played with it. Black and black/white are ground and +12v respectively, which means that red/blue is the trigger wire (you'll only get a voltage reading if the accessory power is on). I saw a tiny voltage across black/white and red/blue (0.08v), so I don't know whether that's just my multimeter or whether that's something significant, so it might be worth checking as well.

marcusus wrote:There might be a short in the trigger wire which is causing it to stay raised? If you do get the multimeter, set it to read the resistance (the omega symbol aka ohms). Make sure the car is completely off (no accessory power). Connect one probe to one wire and the other probe to another. Repeat this for all combinations of wires so that you've essentially connected every wire to every other wire. There's only 3 combinations. If you get a reading that isn't infinity/overload/whatever (aka an actual number) then there's a short somewhere in the line, which means it'll be a real pain in the rear to fix.

This of course assumes that the radio itself doesn't do some sort of shorting across the cabling. I suppose I should just try it on my NB8A antenna and see what results I get (I know mine works, and I've currently got the carpet out).

Okay, I've checked all wire combinations with the multimeter. The only resistance is on the red/blue and black/white combo with reading of 5.7k ohms. As with yours Marcusus, there is a trace of voltage too (0.15v). The power wire reads 12v with the ignition on so power is getting to the antenna socket.

So if I understand you correctly, there must be a break in the trigger wire so replacing the antenna unit obviously will not fix this. Unless I can find the other end of this wire on the back on the radio and check it is connected, this might be a job thats not worth the effort.

What would happen now if I put a wire direct from the trigger wire back to the battery? That should make the antenna motor operate right? This would confirm the motor works. Any reason not to try this?

Quicksilver wrote:Okay, I've checked all wire combinations with the multimeter. The only resistance is on the red/blue and black/white combo with reading of 5.7k ohms. As with yours Marcusus, there is a trace of voltage too (0.15v). The power wire reads 12v with the ignition on so power is getting to the antenna socket.

So if I understand you correctly, there must be a break in the trigger wire so replacing the antenna unit obviously will not fix this. Unless I can find the other end of this wire on the back on the radio and check it is connected, this might be a job thats not worth the effort.

What would happen now if I put a wire direct from the trigger wire back to the battery? That should make the antenna motor operate right? This would confirm the motor works. Any reason not to try this?

Hmmm... the fact that there's resistance across +12v and the trigger wire makes it sound like there's a short between the two wires, resulting in the antenna thinking it's supposed to be permanently raised. I didn't look at the plug in detail, but if it's easy, it might be worth popping out the pin of the trigger wire (red/blue I think) so that it's not connected to the motor. That way, the motor will receive it's power but no signal on the trigger wire, which should make it think that it wants it to be down.

It's usually quite difficult to release the pins from the plug though, but at least it's a free option. Just be careful to not mangle the plug too much.

As for finding it on the back of the radio, it's not difficult to do, but requires pulling the dash and radio out. I know there's a distinct wire for the antenna trigger (it's very possibly red/blue) as I've hooked this up direct to my accessory power so that once I've turned it on, the antenna goes up (stupid head unit without an antenna trigger...).

I wouldn't run it direct to the battery. You'll end up with 12v constantly on the trigger wire (the battery still puts out voltage when the keys are out of the ignition), which is essentially what you have happening now (once you turn on accessory, you're putting some sort of signal down the trigger).

Shame you aren't in Sydney otherwise I'd be more than happy to lend a hand... perhaps some of the QLD guys can help you out? Alternatively, take the car to MX5parts and ask if they have a motor you can quickly borrow and test with to see whether you can make that one raise and retract.

Quicksilver wrote:

CJ5 wrote:when you turn the car on/off do you hear a noise coming from the antennae motor?

No noise. I have a VY Commie with a retracting antenna so I know the motor noise from that.

This could be worth a try...

Quicksilver can you turn the radio off and then VERY GENTLY push the mast down about 10cms.
Turn the radio back on to see if the anntena extends when it is powered..

If it does go back up then one of the ribbons for the up & down movement is broken.

Replacement ribbon kits are available.....