AWD Hub Coil from a Polaris Ranger - how does it work?

[bobhill8]

Hey folks, My son is working on a 2012 Polaris Ranger side-by-side. It is not engaging the 4WD when the switch is flipped. He has done some good sleuthing with the multimeter, but we are trying to determine if this part is doing its job. It is called the AWD Hub Coil. It contains a magnet, that much we know. It has 3 terminals and we have tried powering it, but we don't understand how it works or what the magnet does. If anyone could explain how the part does what is does, that would be a huge help in the troubleshooting. The part fits in the transmission. Thanks.

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1986 Westy
1971 Squareback

[finster]

I don't know anything about rangers but I don't think that's a hub coil. google image search is matching it to a polaris speed sensor...

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"we're here on Earth to fart around" kurt vonnegut

nothing lasts, nothing is finished, and nothing is perfect...

[mukluk]

It's a Hall effect sensor, typically used in conjunction with a tone ring to pick up shaft rotation position or speed.

One wire will be power, one will be ground, and the other is the sensor return. When a metallic object passes the tip of the sensor the signal wire voltage will show a spike.
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1960 Ragtop w/Semaphores "Inga"

[VOLKSWAGNUT]

Yeah thats a speed sensor... which may be ruined now by the voltage applied to it ...

The electromagnetic coil is inside the front axle. It basically works like an AC compressor clutch. It applies a magnetic field to slow down and engage a roller clutch to mechanically connect the front differential to the already spinning front propshaft.

https://www.youtube.com/watch?v=msTYyph2-LE


Here is basic operation

https://www.youtube.com/watch?v=BFODrCS3z7o
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[skills@eurocarsplus]

holy shit

if you put power to the part you're holding, it's dead for sure

if you put power to the wires that hook to that sensor, you 100% smoked whatever is on the other end.

the way they work is .5 (so, 1/2 of 1 volt) positive, ground and then the actual pick up (signal) wire

so, it's +, -, then signal but the terminal arrangement is not really standard so you will need to figure that out

but applying voltage to thing's you're not sure about gets pretty expensive pretty fast
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[bobhill8]

Thanks everyone for the replies. As usual, the brutal honesty of Skills warms my heart. Mistake made. Live and learn. He has a Polaris manual and wiring diagram and the whole nine yards, but if you thought the Bentley Manual was bad, you have no idea. Appreciate the help - I knew you guys would know what it was.
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1986 Westy
1971 Squareback

[finster]

still, it's a lesson learnt - and nobody had to go to hospital which is a plus. it's all in the name of experience...
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"we're here on Earth to fart around" kurt vonnegut

nothing lasts, nothing is finished, and nothing is perfect...