Went over all available threads on this subject here in the forums. New transfer case motor. Tested the CM (blinks 4 times), tested the pigtail, 5 and 8 pin connectors and the only failure I can repeat is the indicator lights on the 4wd and 2wd switch do not light up (test lead on 5-pin, terminals 4 and 5 to ground). Also, the lower dash lights do not light up on the initial bulb test when the engine starts either.

On a suggestion from one thread I adjusted the transfer case motor plate (the 3 small screws holding the plate) to the stops either way with no results.

Pulled and tested fuses. I clearly have power to the control module.

I cannot hear any relays clicking at any time.

Pulled the old electric hubs long ago and installed WARN self locking hubs, pulled appropriate fuse.

Before I pull the TC motor thought I'd see if anyone has any ideas. I've reviewed the '93 wiring schematic and am at a loss as to why the bulb test (lower dash lights )fails on startup.

Can probably use some guidance on how to remove the dash switch to further test and or replace.

Thanks in advance-

 

Look at the diagram, lower left is the dash switch unit

With key on BOTH high and low light bulbs in the switch AND the dash get 12volts from fuse 7
The Controller GROUNDS each light bulb to turn it on

You already know where the controller is, unplug the connectors and locate the Brown/white and Grey wires on the 5 pin connector, those are the 2 ground wires for 2 bulbs each
Turn the key on
Test each of those wires for 12volts, test light or volt meter to local ground, bolt or bare body metal
If no 12volts then fuse 7 is blown, or the light bulbs are burned out

If you have 12volts then GROUND each of those wires and bulbs should come on, all 4, if one doesn't then bulb is burned out

Fuse 7 powers the dash lights as well

Misaligned shift motor contacts could cause dash light indicators to not come on but this test is by-passing that, you are just giving bulbs a ground so they all light up if they have 12v which they should with key on

 

I repeated all the previous tests and the 4wd switch lights and the dash lights still do not come on. The testing shows 12V on terminals 4 and 5 when grounded so it's not a power thing.

More importantly, I still don't have any clicks on the CM relays even though the CM tests OK (4 blinking lights).

Fuses 7 and 17 checked again for continuity. All other dash lights function. Dimmer functions.

As soon as I can figure out how to take the dash panels off to change some bulbs I will do so, any help appreciated. I still need to track down the relay failure though.

 

In the diagram for the dash switch you can see the 3 wires used to select 4high and 4low
They are the other 3 wires on the 5 pin connector

The white/blue wire is the "feed", with no connection to the other 2 wires, thats 2WD
You will want to test connections with OHM Meter/continuity, not voltage

Other 2 wires are Dark Blue and Orange/blue
When you push the dash 4WD buttons you should see a connection from one of these wires to the White/blue wire when that switch closes
If neither has this connection then controller doesn't activate shift motor relays, it's not getting the message to shift to 4WD


Only 1 relay activates at a time
Shift motor is a 12v DC motor, same as power window motor
It has 2 wires, if 1 wire has 12v and the other is a ground motor spins clockwise, if you reverse the wires, 12v is now ground and ground is now 12v then motor spins counter clockwise, window up and window down
And same as power window systems BOTH motor wires are always grounds when not being used
So when the 2 relays in the controller are off both wires to shift motor are grounded, orange and yellow wires
When controller receives the "shift to 4WD" command from the dash switch, it will activate one of the relays to move the transfer case shift rod to 4high, only needs one relay to get 12v because the other wire is already grounded
To move back to 2WD it would use the other relay to reverse direction and move shift rod back to 2WD

But it first has to get the "shift" command, that comes from closed contacts on the dash switch
You can mimic that "shift" command at the controller using a jumper wire between white/blue and orange/blue or dark blue wires, bypassing the dash switch

 

Update-

After following Ron's detailed instructions and double checking the circuits I deduced it had to be something with the new TC motor, so I pulled it off and with wires still connected it functions flawlessly and all the lights behave as they should.

When the TC motor was attached to the case I could feel the relays clicking briefly in the TCM, so I knew the motor was getting the signal, but it just couldn't or wouldn't turn. After removing it from the TC it worked fine.

I adjusted the control plate on the TC motor both ways and in small increments while attached to the TC in hopes that it was an alignment issue, with no results.

So, now it appears the shift control shaft doesn't want to turn easily, I can't get it to budge into 4WD with a vice grip, wondering if there is a special socket or tool to turn it manually and loosen it up? Good clean ATF in the TC, just not used regularly.

I do not know the particulars of how the TC is set up inside. I do have manual locking hubs, wondering if there may be an idea or advantage to that.

Making progress!

 

Make sure there is no "load" on the driveshafts, i.e. put a block behind or in front of a tire then start engine, put it in Neutral, manual or auto, take foot off the brake and let weight of vehicle roll it against the block under the tire, then shift it to park and shut off engine

Now the shift rod on transfer case should be EASY to turn with pliers

In this pic shift rod is in 2WD(2H): https://www.therangerstation.com/tec...ft_motor-2.JPG
It will only turn counter-clockwise from this position and be easy to turn to 4H and then 4L, and then clockwise back to 2H, it doesn't go 360deg
If its not easy to turn or can't turn then transfer case will need to be pulled out and opened up


Yes, the shift motor has a thermal limiter switch, like power window motor, if it can not turn when powered on it shuts off because AMPS heat up limiter and opens the connection, this is inside and part of the motor.
That's also why relay will click on and then click off right away, because there is no movement of the sensor wheel in the shift motor housing