How do I diagnose the transfercase actuator motor?

[BillRod]

Hi All

93 Ranger, I posted the question earlier about the 4x4 dash switch earlier today.

Tomorrow the weather is supposed to be above freezing so I want to diagnose the 4x4 actuator motor.
I recall there is a specific procedure because I went through this a couple years ago when I had the same issue with my wife's 94 Ranger.
I can't find the post or sticky on how to diagnose the actuator.

Thanks
Bill

 

[Earl43P]

http://www.therangerstation.com/tech_library/transfercasetroubleshooting.htm

 

[BillRod]

Hi Earl

Thanks for the info.
I stepped through the diags as listed.
All looked ok until step 5c when I probed the orange wire on the motor.
No voltage there.
I do have continuity between the orange on the 4x4 module and the shift motor. Same for the yellow.

Step 6 A is a puzzler though.
I back probed the blue terminal 2 wire on the 5 pin and when I pressed the 4x4 switch I have 4.93 volts instead of 12v.
I then back probed the white/blue terminal 1 wire and I turned the key I have 4.98 volts.
Both of these should have 12v instead of less than 5.
Where does the 12 volts come from that should be at terminal 1?

Any thoughts?

Thanks
Bill

 

[Earl43P]

My first suspicion would be a bad ground (the Black wire).
Assuming you used that as your reference when checking power.
Try using a good chassis ground for those same voltage readings.

Since you are getting "some" voltage through the 4x4 module to the shift motor plug, ground could be corroded. I'd expect it to be located near the 4x4 shift module.

 

[BillRod]

I actually used 2 different bolts for the ground.
One on the jump seat frame and one on the body.

I agree the more I think about it the ground seems logical.
So the black wire in the 8 wire pigtail bundle is the ground?
Is that just bolted somewhere to chassis ground?
Any idea where or how close it might be to the actual module?

After posting I started trying to trace the harnesses before it got too cold outside. I will try again tomorrow if it stays above freezing long enough.

Any other thoughts?

Thanks again!
Bill

 

[BillRod]

Ok, warm enough out today so here's what I found.

Ground
Black wire on the pigtail ohm's out perfect for a good ground.
I ohm'd it between that connector and a couple of chassis ground spots.

Power
Green wire with yellow stripe has 12 volts constant, key off or on.
White wire with purple(?) stripe has 12 volts with the key on.
I used both the chassis grounds and the black wire ground connector in the pigtail for the meter and got a full 12 volts each time.

So it looks like there is good ground and power to the module is good.
But since I only got less than 5v on the other side of the module it sure sounds like the module itself is bad.
Even though the red light blinked as should when I followed the diag instructions.
What do you think?

Thanks
Bill

 

[BillRod]

Went down to the U Pull n Pay and got another module for $15.
Installed and made no difference.
U Pull n Pay has a great return policy so I returned the module for credit then got another actuator for $25.
Installed and everything works now.
All that is left is to return my old actuator for the $7 core charge.
That will leave a total repair cost of about $18!

Thanks for the help and the info Earl!

Bill