Not the usual antenna problem

[Timoss]

I have searched, but can't find anything on this issue: My antenna (97 fzj) goes up when I turn the radio on--and won't quit trying to go up even after it's fully extended. It just keeps grinding--whirra-whirra-whirra. Turn the radio off and it goes back down. Switch on dash has no effect. Since the antenna is clearly "working" physically, it's not the usual broken gear/mast problem. The FSM, however, doesn't show a wiring diagram or address this problem.

Any ideas on where to look?

Thanks!

Timoss
88 62
97 80

 

[Scamper]

It's been a few years since I had my antenna motor out for a mast repair, but as I recall, there is a set of contacts in the motor assembly that works similarly to the windshield wiper motor. Upon reaching the limit of extension, the contacts release some relay that holds the motor on until it's extended (or something like that). I can think of two possible reasons for your problem: either the contacts are bad (broken, bent, worn, etc.), or the relay is sticking. I'd be inclined to think the contacts are bad since when you turn the radio off, the antenna retracts. I'd pull the antenna motor and look at those contacts, being sure they are clean and not pitted, broken or something.

 

[Timoss]

Thanks for the ideas. Isn't it just as likely it is the relay itself? The radio power on/off signal is actuating the relay properly. But that doesn't mean the relay is correctly passing on the signal to stop the up movement that comes from the contacts in the motor you describe, right?

I know where the antenna motor is, but where the heck is the antenna relay?

Thanks!

Timoss
88 62
87 90

 

[Scamper]

A quick look at the EWD and it appears that there is no relay for the antenna, but there is an Auto-Antenna ECU in the PS kick pannel.

 

[G-Cat]

I am having the exact same problem. Mine is on a 1997 with a 2-year-old mast. I'll be interesed to see what the fix is...

 

[Timoss]

Cool, thanks for the diagram. I will investigate the ecu....

Timoss
88 62
97 80

 

[Timoss]

Finally go the wiring diagram

Ok, so I finally tracked down the wiring diagram for the auto/manual antenna. Can anyone looking at it provide some troubleshooting tips based on this diagram? I pulled the antenna ecu and it LOOKS immaculate, but my electrical knowledge is very shallow. Again, the problem is: turning the radio on causes the antenna to go up--but it just keeps trying to go up and won't quit. The manual button on the dash has no effect under these circumstances. Turning radio off (or switching to CD or Cassette) causes the antenna to go down normally.

Thanks!

Timoss
88 62
97 80

 

[TRICRUISERS]

I have searched, but can't find anything on this issue: My antenna (97 fzj) goes up when I turn the radio on--and won't quit trying to go up even after it's fully extended. It just keeps grinding--whirra-whirra-whirra. Turn the radio off and it goes back down. Switch on dash has no effect. Since the antenna is clearly "working" physically, it's not the usual broken gear/mast problem. The FSM, however, doesn't show a wiring diagram or address this problem.

Any ideas on where to look?

Thanks!

Timoss
88 62
97 80

Hi, I know your post is from a long time ago, but, I now have this same issue. Worked fine for years, then started this noise. Driving me crazy trying to source the problem, which is how I have ended up here.
I have done the obvious too, and dismantled the motor gearbox, pulled the cord (which appears perfect), checked all gears, unsoldered both relays from the circuit board and they tested fine. If the antenna (minus cord) is connected to the harness and powered up, the motor runs as if extending the antenna, then stops seemingly after a predetermined time, and makes no noise. Turn the power off, and the same applies.
Can you help at all with this please?
Regards, TRICRUISERS.

 

[LINUS]

^^^ what’s the socket to the ECU doing?

-checking your manual control switch would be my start.

-Kudos on the search BTW (esp for a 1st post) — you dusted off a oldie!

 

[TRICRUISERS]

^^^ what’s the socket to the ECU doing?

-checking your manual control switch would be my start.

-Kudos on the search BTW (esp for a 1st post) — you dusted off a oldie!

Hi. Thanks for your rapid reply, especially considering our time zones.
Not quite sure what you mean by "socket to the ECU".
The antenna was bought early 2016 from a wreckers and came with the relay and indash over ride switch. The harness socket with matching wiring was already behind the pop out cap for the antenna over ride switch in the dash, but that never has worked and is no longer in place.
Regards, TRICRUISERS

 

[Kernal]

One WAG. The auto up/down antenna assembly (as far as I know) has two harness connectors compared to the one connector of the push button up/down version.

So wondering if the second connecter is disconnected (to the Auto up/down ECU?), will the auto-up down antenna then go up/down if the buttons are pushed??

 

[TRICRUISERS]

One WAG. The auto up/down antenna assembly (as far as I know) has two harness connectors compared to the one connector of the push button up/down version.

So wondering if the second connecter is disconnected (to the Auto up/down ECU?), will the auto-up down antenna then go up/down if the buttons are pushed??

Thanks for coming back to me. The manual indash over ride switch has never worked and is not in the vehicle, but the auto Ign powered switching is fine.

 

[retlaw]

I'll just add what I've learned so far about my 97 LX antenna....still learning btw...

The LX and, I believe, the 97 LC have TWO connectors on the antenna assembly. One is motor power (reverses polarity for up and down) and one is for what Toyota calls the antenna relay which is magnetic sensor located right on the antenna assembly. I think it sends position info to the ECU (yes the ECU is in the passenger kick panel BUT I think mine is labeled antenna relay to make it even more confusing).....It actually does have two relays that control the polarity (up/down) to the motor which are activated by the manual buttons on the dash and the radio being powered on/off. The manual buttons on the 97 are not the same as earlier models and are simply sending a signal to the ECU...the earlier models had switches that actually carried 12 volts to the motor.
When pushing the manual buttons on the 97 the ECU controls the relays on the ECU board for what appears to be a timed event...enough time to go up or down and then shuts off. This seems to work even without the second connector ("relay") connected. Note: the radio must be ON for the manual buttons to work....which also means the purple wire from the radio to the ECU has to be connected for the ECU to know the radio is ON.

I still dont know what the second connector (antenna "relay") does exactly... since there is a timer on the ECU why is a position sensor needed? Maybe its to avoid activating the antenna up/down when its already up or down.

To test: Put a volt meter on the 2 pin motor connector. Turn radio ON. You should see 12 volts on the meter for a timed period then 0 volts. Turn radio OFF and the same thing only polarity reversed. The buttons will cause the same response IF the radio is ON.
Note: mine tests this way except the down button doesnt do anything....I have not checked this out any further....I have the OEM non-powered antenna right now and have been concentrating on more pressing issues.

Can anyone add to or correct my post?

 

[Bud_Dude]

I'll just add what I've learned so far about my 97 LX antenna....still learning btw...

The LX and, I believe, the 97 LC have TWO connectors on the antenna assembly. One is motor power (reverses polarity for up and down) and one is for what Toyota calls the antenna relay which is magnetic sensor located right on the antenna assembly. I think it sends position info to the ECU (yes the ECU is in the passenger kick panel BUT I think mine is labeled antenna relay to make it even more confusing).....It actually does have two relays that control the polarity (up/down) to the motor which are activated by the manual buttons on the dash and the radio being powered on/off. The manual buttons on the 97 are not the same as earlier models and are simply sending a signal to the ECU...the earlier models had switches that actually carried 12 volts to the motor.
When pushing the manual buttons on the 97 the ECU controls the relays on the ECU board for what appears to be a timed event...enough time to go up or down and then shuts off. This seems to work even without the second connector ("relay") connected. Note: the radio must be ON for the manual buttons to work....which also means the purple wire from the radio to the ECU has to be connected for the ECU to know the radio is ON.

I still dont know what the second connector (antenna "relay") does exactly... since there is a timer on the ECU why is a position sensor needed? Maybe its to avoid activating the antenna up/down when its already up or down.

To test: Put a volt meter on the 2 pin motor connector. Turn radio ON. You should see 12 volts on the meter for a timed period then 0 volts. Turn radio OFF and the same thing only polarity reversed. The buttons will cause the same response IF the radio is ON.
Note: mine tests this way except the down button doesnt do anything....I have not checked this out any further....I have the OEM non-powered antenna right now and have been concentrating on more pressing issues.

Can anyone add to or correct my post?

My older 95 Land Cruiser factory antenna was strictly manual operation, push the button to go up or push the button to go down, and it made the nasty clacking sound when it reached the end of its motion (ie all the way up or all the way down). I now have a 40th Anniversary 97 Land Cruiser and just replaced the broken aftermarket power antenna assembly with a brand new stock Toyota power antenna from the dealership (p/n 86300-60050). I can see that there are two connectors at the antenna access hole where the antenna assembly is installed, my new antenna has only the 2 pin connector (A8). It initially appeared to go up and down fine, but when I turn off the the key the antenna retracts, bottoms out and starts with the nasty clacking sound for about 20-30 seconds.... It's very very annoying and I cannot believe Toyota designed it to do this; no customer would put up with that kinda racket. So, on studying the 97 Electrical Wiring Diagam manual (pg 118) you can see the diagram is quite different from the 95; on the 97 there's an extra module called the AUTO ANTENNA ECU (A28) that appears to control the antenna automatic up and down operation with the activation of the radio (purple or violet wire). I also appears to have a motor current sense circuit that I am going to guess is intended to stop the antenna motor when it reaches the ends and starts clacking. I'll do more research on this tomorrow, but I am wondering if this extra connector next to the antenna access hole might be connector A27 - Auto Antenna Relay... No idea what it does. Maybe my ANTENNA ECU is not working correctly.

At this point I'm a little bummed after spending all the money for the factory antenna only to find out it doesn't work properly...
Does anyone have any other knowledge on this module/antenna operation?

 

[TRICRUISERS]

My older 95 Land Cruiser factory antenna was strictly manual operation, push the button to go up or push the button to go down, and it made the nasty clacking sound when it reached the end of its motion (ie all the way up or all the way down). I now have a 40th Anniversary 97 Land Cruiser and just replaced the broken aftermarket power antenna assembly with a brand new stock Toyota power antenna from the dealership (p/n 86300-60050). I can see that there are two connectors at the antenna access hole where the antenna assembly is installed, my new antenna has only the 2 pin connector (A8). It initially appeared to go up and down fine, but when I turn off the the key the antenna retracts, bottoms out and starts with the nasty clacking sound for about 20-30 seconds.... It's very very annoying and I cannot believe Toyota designed it to do this; no customer would put up with that kinda racket. So, on studying the 97 Electrical Wiring Diagam manual (pg 118) you can see the diagram is quite different from the 95; on the 97 there's an extra module called the AUTO ANTENNA ECU (A28) that appears to control the antenna automatic up and down operation with the activation of the radio (purple or violet wire). I also appears to have a motor current sense circuit that I am going to guess is intended to stop the antenna motor when it reaches the ends and starts clacking. I'll do more research on this tomorrow, but I am wondering if this extra connector next to the antenna access hole might be connector A27 - Auto Antenna Relay... No idea what it does. Maybe my ANTENNA ECU is not working correctly.

At this point I'm a little bummed after spending all the money for the factory antenna only to find out it doesn't work properly...
Does anyone have any other knowledge on this module/antenna operation?

Hi and welcome to the complexity of Toyota antenna circuits. I had all the issues you mentioned and decided there must be an easier, cheaper and repeatable way round the problem. Go to your local auto parts supply and buy a good after market unit and put that in. No big deal. Please see my post of July 18.

 

[Bud_Dude]

Hi and welcome to the complexity of Toyota antenna circuits. I had all the issues you mentioned and decided there must be an easier, cheaper and repeatable way round the problem. Go to your local auto parts supply and buy a good after market unit and put that in. No big deal. Please see my post of July 18.

I beat it into submission with a hack of the AUTO ANTENNA ECU and it's working identically to my old 95 now. See my hack here: Loud gear grinding noise after power antenna lowers. which references and builds upon a prior hack by @Dorz that can be seen here... antenna relay bad...want to bypass for manual control
All is right with the world again and I can continue on my other projects here.