Stereo Connector C - Auto antenna

Milo · 10-27-09, 07:20 PM

Hi,

I've just dropped an aftermarket stereo into my Sahara and the auto antenna doesn't work correctly (It'll only go up by 150mm). Looking through manuals and wiring diagrams there is an extra plug from the OEM radio tuner. Wiring diagram lists this as Connector "C". It has two wires (coloured R-G and R-L). The adapter harness that I used has the other wire which is connected to the stereo. I am using the two grey plugs behind the stereo and have removed the factory amp. Being a late model Sahara it has the 9 speaker setup with the 10(?) disc stacker and has only a two button antenna control (Auto and Down).

The question that I'd like to answer is what do those two wires do? Has anyone tried to feed a bit of power down them or hook them up to something else. My guess is they feed back the station setting so that the auto antenna ECU can adjust the antenna length to suit the frequency of the station. The wiring diagrams show the Auto Antenna ECU as a box only.

Any help or suggestions on tests that I can do would be appreciated. I have trawled through the boards looking for answers to no avail.

Cheers!

greentruck · 10-28-09, 09:58 AM

Michael,
Lots of info in the archives on this. I just R&Red the antenna assembly when swapping out the OEM head unit from an aftermarket on my 80. Search is your friend here, as I found what I needed there and I remember seeing what will probably help you there, too.

The '97 is a different power antenna switch set-up than earlier years, so I can't really give you good info on your problem. I also kept the OEM amp, so I only needed to buy a Toyota adapter harness for the aftermarket head unit and plug it into the truck's harness.

Milo · 10-28-09, 07:16 PM

Mike, Thanks for the reply. I have searched and searched and read and read. I did find a lot of information, however, nothing for my specific issue. I still don't know what the extra connector is for.

greentruck · 10-28-09, 11:20 PM

Yeah, it's kinda different between the years as I remember. Once you take the stock amp outta the chain that further complicates things.

I think when things are working right, you should be able to push the auto side of the switch and it will go up until you release it. Then, when you turn the ign off, it will retract. I suppose auto means it should remember what height to return to when you turn the ignition or radio back on, when it's working properly or course.

Push down on the switch to manually retract.

All this is controlled through a ECU on the PS.

On the 97, the antenna pops up to about 90mm (a little over 3 inches) whenever you turn the radio on; goes down when you turn the radio or ignition off. Push up to manually set antenna height. This is with the antenna wire on my head unit hooked into the antenna wire in the Toyota adapter harness I bought.

Sorry I can't be more insightful. Heck, the first LC wagon I owned (a FJ55) didn't even come with a radio

Milo · 10-29-09, 02:00 AM

Hmm... Well you've given me a few more things to check. Thanks.

The amp has been taken out. I tried to put that back in the other night but it then just blew a fuse. I might try putting it back in with the original stereo but leave the C plug disconnected to see what happens. I'll also try it with it in to see if maybe the antenna has become damaged and it's just coincidence that its at the same time.

I'll also try playing with the buttons a bit more. The auto button is a latching button while the down button is just an instantaneous. It does go down when the stereo is turned off and it'll go down half an inch when you press the down button. Weird thing. I might try feeding power to everything just to see what happens.

The other thing is that the antenna used to change height depending on whether you had it on AM or FM. I suspected it changed height with station too but I never tested this to confirm. Might have a look at that when I test the original stereo.

What I need is a circuit diagram for that Auto Antenna ECU.