Testing t-case shift motor?

[chrisb]

Hi there,

I have my shift motor from the transfer case off my vehicle... isn't working right now.... I'm about to clean it up and then test it.

I've read the pages on testing it, but I have one question about applying the voltage to it to get it to rotate. The pages said to apply "+12v to one pin and -12v(ground) to the other" ...

Is that -12v or is it ground?

What type of supply can you use to test it? Will the power from a computer power supply be enough?

Thanks,
Chris B

 

[Robert]

It should be ground. As far as I know -12V isn't available on the Explorer.

 

[chrisb]

Okay thanks...

If it is +12v and ground, where should I feed it from?

I can feed 12v and ground from a PC supply or from a panel which is part of my audio system (ie. right from the battery).

Which should I do? I don't want to feed the motor too many amps and burn it out?

Thanks,

Chris B

 

[Robert]

You can't feed it too many amps. All you could do is pull too many amps from your power supply. It doesn't work the other way around. For example if the solenoid coil is a 10 ohm coil and you hook 12V up to it, it will require 1.2A. If you used a power supply that can't deliver 1.2A it would overheat the power supply and probably burn it up or blow a fuse. If you hooked up a battery to it that has 50A in it, the solenoid would only pull 1.2A. These numbers are just an example, I don't know how much current your solenoid actually requires. A 10A power supply or the car battery should be more than adequate.

 

[chrisb]

Thanks for the info... makes sense...

Chris

 

[chrisb]

Hi all...

Got the motor working by taking it apart an cleaning it.

One note, you don't have to cut any wires to remove the motor from under the truck. Just removed the red plug inside the connector and then pull out the three wires by moving the catches away from the pins.

Also, if the motor isn't working, you don't have to remove to security torx screws... that just goes to the sensor end of things... just remove the bracket and the two long bolts underneath and clean the copper part of the motor and the little spring loaded contacts.

Later,
Chris Bright