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Shift motor woes. Shiftster still a thing?


ericbphoto

Old Redneck just wingin' it.
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My credo
In theory, theory and practice are the same. In practice, they are different.
"Then the computer must have used a pulse width modulation signal like they use for the fuel injector"

I really doubt it. The controller can react faster than you or me. It sees the motor switch contacts change and cuts power. You and I have to watch for the light to come on and then rely on our reflexes. We are slow.
 


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RonD

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The Rangers 4x4 electric control systems send vehicle voltage to shift motor, so 12.5v to 14.5v(engine running)

No PWM was used

They all used two 5 pin Relays, one relay for each motor wire, when a relay was OFF(pin 87A connected to pin 30) that motor wire was grounded
Pin 30 was motor wire
Pin 87 was 12v
Pin 87A was Ground
So status of both motor wires is Grounded unless relay was activated

The controller would then only need to activate 1 of the relays, making that wire 12v(14v) to get the shift motor to turn
So it could turn shift motor either way, like a power window motor, by activating just one of the two relays, since the other wire was already a ground

The 5 Contact wires have 1 common wire then 4 position wires, 2WD, 4H, Neutral, 4L, yes Neutral is a selection just not included in electric shift setup but could be added
Yes, you could send 12v to contacts and then use 4 lights to indicate position, the controller used 5volts, and grounded the dash bulbs as needed on most years
The 4WD dash bulbs get 12v with key on, and are grounded for bulb test, then keep getting the 12v but are not grounded until controller ground them

You could do the same, use four 12v bulbs that all get 12v key on, but no grounds, then use common wire as ground, and each contact wire to one of the 4 bulbs, so they would light up when contact was aligned
 

ecgreen

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31
I don't know what voltage the computer used for the motor, but putting 12v on it makes it move very fast. This can be a good thing I think, giving it a good jolt after it sits all summer long. As long as you don't hold the switch up or down forever, I don't think you will burn the motor up. That is why I was always careful and just bumped the switch momentarily. I would bump it two or 3 times for low range. You could sometimes hear the gears engaging and the truck would jerk, just like a manual lever sometimes things don't want to line up inside the transfer case. Just inching forward just a bit will sometimes help it engage.

When I was going back to 2wd, I would always hit it 2 or 3 times to make sure I was all the way out of 4x4. All I then had to do was back up 8-10ft to unlock the hubs, and I was on my way.

I used a 30 amp circuit breaker to the battery because I had it laying around. You could use a smaller one if you wanted. Just something to cut power in case something happens to the wires.

You have to keep your head on straight using this. No shift on the fly anymore, unless you have converted to manual hubs and have them locked in. And you always have to be stopped to shift into 4x4 low. I never had any little kids in my truck, but if you do, I would suggest doing something so they can't play with the switch.

Being able to rely on the 4x4 system is a major relief when having one of these trucks.
I have currently diagnosed a bum shift module in my BII and this might be my answer. Its the smartest fix I have seen yet. Thanks for all the info!
 

ecgreen

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Total Lift
1.5
Tire Size
31
So I am going to attempt to wire the motor to a switch like franklin2 did. I'll do a write-up if successful.
 


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