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940 944T Antenna reversed polarity

redblockpowered

redblockpowered

bad username length
Joined
May 5, 2015
Location
Swampscott, MA
I put an antenna mast in my car, and it seems to operate correctly other than that everything is backward! It parks in "deployed" position and the switch seems to lower it rather than raise it. This car has an aftermarket radio (wired correctly, it seems) the switch works, the motor just runs in the opposite direction it should. I had it apart and couldn't find any evidence that the motor or wiring had been tampered with other than the addition of the aftermarket radio.
 
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redblockpowered said:
I put an antenna mast in my car
Click to expand...
From a Volvo, Chevy, Maserati, or Rickenbacker?

It parks in "deployed" position and the switch seems to lower it rather than raise it.
Click to expand...
Stock Volvo antenna should have 3 wires.

Pin 1 green/red - Always connected to power.
Pin 3 red (changes to green/grey going to switch) - "Up" trigger.
Pin 4 black - Always connected to ground.

With power applied to pin 3, a relay inside the antenna should raise the antenna.
With power removed from pin 3, the relay should "relax" and allow the antenna to lower.

the switch seems to lower it rather than raise it.
Click to expand...
Which switch? The stock one?

other than the addition of the aftermarket radio.
Click to expand...
From a BMW, Ford, Lancia, or Studebaker?
 
MasterBlaster said:
From a Volvo, Chevy, Maserati, or Rickenbacker?

I didn't add an antenna. I replaced the mast, which had a broken nylon cable as most do. Everything else was already there.


Stock Volvo antenna should have 3 wires.

Pin 1 green/red - Always connected to power.
Pin 3 red (changes to green/grey going to switch) - "Up" trigger.
Pin 4 black - Always connected to ground.

This is what I have.

With power applied to pin 3, a relay inside the antenna should raise the antenna.
With power removed from pin 3, the relay should "relax" and allow the antenna to lower.

Yes. Applying power to pin 3 lowers the antenna in my car.

Which switch? The stock one?

Yes.

From a BMW, Ford, Lancia, or Studebaker?

It's a Pioneer DEH-X6600BT. So none of the above.
Click to expand...

Does that help?
 
Let me have a go at translating. You replaced the mast in a previously working 940 antenna and now it extends when you shut the radio off and retracts when you need it up. :)

Am I close?

radio3945.jpg
 
Hmmm...
Any chance you managed to install the mast backwards?
Normally, you turn the radio on, wait for the motor to stop trying to raise the non-existent antenna, insert the new nylon strip so the teeth are on the inside of the "scroll" , then turn the radio off and let it gently suck the strip in.

If you somehow (almost impossible) had the teeth facing the wrong way, then turned the radio on while forcing the strip in, it may (still almost impossible) pull the strip in on the out stroke. The strip would have to bend sharply to get onto the inside gear backwards, hence "almost impossible".
 
cleanflametrap said:
Let me have a go at translating. You replaced the mast in a previously working 940 antenna and now it extends when you shut the radio off and retracts when you need it up. :)

Am I close?

radio3945.jpg
Click to expand...

Affirmative. And the mast is NOT installed backwards. I pulled the mast out and connected the motor with its cover removed and confirmed. Turn radio/car off, motor moves "outward". Turn radio on, motor moves "inward". Multimeter readings confirm that the wiring is correct as previously described by MasterBlaster.

As installed in the car, at the connector to the motor:

Pin 1 green/red: Battery voltage (12.2 volts as measured)
Pin 3 green/gray: 12v switched (11.8 volts as measured). When power is applied to the switch, the antenna is lowered. Otherwise, the antenna is raised.
Pin 4 black: Grounded. Verified good ground with multimeter, forget the exact reading.
 
I've seen 2 different wiring and relay setups on power antennas that I have installed in my 88 765. Antenna mast was missing, aftermarket rubber ducky antenna installed, but assembly still inside back of car. Found antenna assembly from 740/940 wagon in junkyard. Rearranged wiring and relay to fit my 765. Later antenna mast got bent in parking garage. Found another antenna assembly for parts. Used parts from the 3 to make one that is slightly bent, but still goes up and down.

Switch? As in the dash mounted switch for lowering the antenna for car wash or parking garages?
 
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Remove 2 screws holding "tin can" motor housing in place.
Rotate housing 180 degrees (without pulling it off!).
Replace 2 screws.
Report back.
 
MasterBlaster said:
Remove 2 screws holding "tin can" motor housing in place.
Rotate housing 180 degrees (without pulling it off!).
Replace 2 screws.
Report back.
Click to expand...

Liked this suggestion but didn't have time to try it until now due to exams. No dice. I suppose I could fix it by soldering the wires coming off the motor controller the other way around, but that certainly doesn't solve the issue of how this happened in the first place.
 
redblockpowered said:
Liked this suggestion but didn't have time to try it until now due to exams. No dice.
Click to expand...

Oh, well. So much for the Internet. I haven't felt like taking mine out and disassembling it, but one theory was that the magnets were bonded to the can, and turning it would flip the "North" and "South" poles and make the motor run the other way.
I suppose I could fix it by soldering the wires coming off the motor controller the other way around, but that certainly doesn't solve the issue of how this happened in the first place.
Click to expand...
Any chance you swapped in a battery from a old British car at the same time as the mast? They used to be Positive-ground instead of Negative-ground.

Or maybe you moved to Australia? Their toilets supposedly swirl in the opposite direction, maybe their electricity flows backwards too?
 
MasterBlaster said:
Oh, well. So much for the Internet. I haven't felt like taking mine out and disassembling it, but one theory was that the magnets were bonded to the can, and turning it would flip the "North" and "South" poles and make the motor run the other way.
Any chance you swapped in a battery from a old British car at the same time as the mast? They used to be Positive-ground instead of Negative-ground.

Or maybe you moved to Australia? Their toilets supposedly swirl in the opposite direction, maybe their electricity flows backwards too?
Click to expand...

Ah, I should have known using the battery out of my old MGA was a bad idea. All the songs on the radio were backwards, too. I feel a strange urge to worship Satan. :lol:

Really I'm pretty confused by this issue. I don't know how it got this way but I guess at some point you just have to shrug and say "it's old" as you do some very strange power antenna surgery.
 
MasterBlaster said:
Oh, well. So much for the Internet.
Click to expand...

Along the same lines as your suggestion, I wondered whether the usual explanation for mysteries could be in play here. That usual explanation is the one seemingly unimportant clue that fails to reveal itself in the story of what was done. We have to guess.

My guess was gonna be something like the pins got swapped in the plug, but that seems unlikely. Red and white run the motor. Might be easier to unpin and swap them than unsoldering them at the motor.

radio3499.jpg


MasterBlaster said:
Or maybe you moved to Australia? Their toilets supposedly swirl in the opposite direction, maybe their electricity flows backwards too?
Click to expand...

And again, I checked to see if there were any current geomagnetic polarity reversals in progress, but figured I might draw the ire of the OP with my bent sense of humor. Now I see by his response to you it would have been OK.
 
Resoldered the red and white wires going to the motor backwards.. Works as designed now, not that that really provides a satisfying answer to whatever the hell caused this issue. I'm officially blaming ghosts.
 
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