'91 - Power or Winter modes not working

[twoopah]

The vehicle is a 1991 Trooper V6 Auto, and I'm having no luck getting the Power or Winter modes to engage.

Firstly, the Winter-mode button is broken. That's not helping anything.

The Power-mode button is intact, but doesn't light up or make any difference when pushed. I read the manual, which indicated to push the button with the gear selector in D.

Does anyone have a diagram or troubleshooting steps of this area? I thought of locating the correct wires and shorting them to see if it's a button problem, or something else.

The small panel where I'm expecting the light to appear also doesn't illuminate when first turning on the vehicle, as I was expecting. Should it?

Thanks!
Bart

[stompin60]

I have never had any real need for these modes. In fact I have accidentally hit them and thought I was going to screw my tranny up. My guess is that someone along the way disconnected them as they to rendered them useless. They only start your vehicle off in 3rd, well one of them does for sure. The panel does not light up, unless one of the modes are engaged.

[twoopah]

We're going to be moving to a very heavy snowfall region this Winter, and thought the Winter mode (the one that starts you off in 3rd) might actually prove rather useful.

Also, we're going to be pulling a trailer to get our belongings moved over the Rockies, so I believe the Power mode might also prove useful, such is the reason I would like to get them functioning again.

[stompin60]

both good reasons. I have never had to tow anything with mine. As you have probably noticed, these things are geared pretty low so that should help you out. As far as the snow goes, ( of course with good tires ) I have literally drove about 70 miles stop and go mostly in the middle of the night ( nothing had been plowed ) through 2 feet of snow and barely spun the tires let alone had any trouble or fear of getting stuck. I was however pushing snow down the road....

[twoopah]

Okay! I figured it out on my own - here's some things you may wish to check for in the Power and Winter mode buttons, and a little information on the wiring:

To get at the wiring and buttons, do the following:
With the vehicle off, apply your parking brake and/or block the wheels.
Put the gear selector in 'L' or '1'.
With a phillips-head screwdriver remove the three screws in the base of the main shifter knob.
Push the selector button in and pull the knob up along the length of the selector's shaft and the grip will come free. You'll probably have lost the button at this point so dig around and find it. There's a spring about 1.5" that should have stayed inside the grip - make sure you still have that, too.
Unscrew the 4WD mode selector's knob - just spin it to the left.
You now need to free up the between-seat console. Four screws hold this in place; 2 on the sides near the front and 2 on its sides at the rear.
Once it is loose move it out of the way a bit to remove the screw at the rearward-facing base of the shifter console. Two more screws on each side towards the front of the shifter console hold this in place.
Move the main gear selector into whichever gear you need so that you can start to wiggle the console off and forward. You won't get very far, but should now have enough room to reach your hand to the frontward-facing side of the console and disconnect the two wiring harneses. They both have little tabs on the firewall-side that can be compressed with a finger to free up the harnesses.
Squish the rubber boot on the 4WD selector. It stays on, so you should be able to wiggle it through the hole and completely remove the shifter console.
You now have access to the wiring, buttons and lights underneath.

Wiring information and some troubleshooting:
The harness for the buttons has 5 wires; 3 are for the switches and 2 for the LED's that illuminate them.
Both buttons are push-button types that complete the circuit momentarilty to signal the transmission unit to turn on whichever mode you're looking for.

Switch harness:
Blue wire /w green stripe = power button (switched)
Blue /w black = winter button (switched)
Black = Common to both switches
Green w/ red = 12V (+) for LED's that illuminate buttons
Red w/ green = (-) for LED's

By momentarily shorting either of the two switch wires to the black wire in the 5-wire harness, you should be able to rule out whether your buttons are faulty or not. In my case, the Winter button was broken off and was completing the circuit and not allowing the Power mode to engage.

You don't need to reinstall the console to test, just replace the gear selector grip. Make sure the engine is running and gear selector is in 'D' when you momentarily short the above switch combos. If the mode you selected is working, you should have 12 volts to the one of the corresponding wire combinations in the indicator light harness.

Indicator light harness:
Blue wire = 12V (+) for 'winter drive' light
Green wire = 12V (+) for 'power drive' light
Yellow wires = (-) for both lights

To reinstall the consoles and wiring:
Simply reverse the order of the removal steps.
Note for re-installation of the main gear selector grip: Make sure the angled side of the plastic 'arrow' is facing left and, with the spring and button on grip installed and pushed in, slide the grip back down the shaft and reinstall screws. Check to make sure that the button and selector operate properly before going anywhere.



That's all I got - add anything you think might be relevent. This is pretty basic, so I hope I didn't insult anyone by posting it, but I thought I would share it anyways. Using the info I gathered, I'll be installing some basic push-button switches in place of the OEM buttons, if I can't find a replacement from a junkyard.

twoopah

[trooperbc]

Originally Posted by twoopah

....This is pretty basic, so I hope I didn't insult anyone by posting it, twoopah

nice write up. it's the basic stuff we're all dealing with here.

hope this will get archived someplace for the next guy...


thanks


//bc

p.s. one thing i'm surprised at is that the reading is 12V, since these switches provide the info to the trans computer. i would have suspected less, like the 5v that is used for lots of the engine sensors etc that provide data to the engine computer. i wonder if it's the same for the 1992 on troopers?