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Do any of the four-wheel drive indicator lights illuminate or any warning light come on when you tried to engage the four-wheel drive and it does not work? When was last time you had the four-wheel drive engaged? Do you have a manual lever to engage high and low?Skyvisions
Unfortunately there's no easy way to test the systems. You need to use a voltmeter and have a pin out chart of all of the four-wheel drive computer inputs and test all of the electrical inputs and ground circuits. If all the power inputs and grounds test good then it's a matter of checking all of the switches like the one in the lever and at the transfer case and front actuator assembly in the front differential. My concern is that there is no power to the red wire to the switch on the lever. This should have voltage on it.Skyvisions
The connector is a 16 pin connector and looks at following. Is located right near the airbag computer but I can't find a specific diagram that shows a good location. The computer number and description should be on the top of the computer itself.
i tried putting 12v to the blue wire and ground to the white wire and i could hear the motor click just barely then i reversed and grounded the blue and 12v to white and same thing, just a slight click like it wanted to but couldn't. am i doing this right or not, i dont understand what your saying about changing the polarity. we put vaccum to the actuator on the front diff. and it seems to be working, also both vaccum switching valves is working. i can take the wire loose from the ADD and ground one side of it and theXXXXXwill come on so i know the light works now. seems like all the wires are good just maybe one of the switches or the motor is bad , ANY ADVICE WILL BE MUCH APPRECIATED.
can i take the motor off the back of the transfer case by taking the 3 bolts out and pulling it off or does it consist of more. thats what i am thinking is wrong is the motor is stuck.
I don't mind working through another problem but the information that I gave you was invaluable. To pay someone for the diagnostic information I provided to you would've cost you several hundred dollars. To come to a total resolution given the type of format were working in with your particular problem is probably unrealistic. Let your conscience be your guide.
This being said if you check the wire harness that goes up to the combination switch you will find a red wire with the yellow tracer it is pin number 12. This wire should have 12 V when the headlight relay is turned on either in the low or high beam position. When you push the high beam switch or lever to the high beam position this red wire with the yellow tracer should go to 0 V if it does not the switch contact for the high beam position in the switch is bad. If you ground this red wire with the yellow tracer with a jumper wire it should turn the high beams on.Skyvisions