4×4 Troubles

I have a 91 Ford Explorer, and this morning all the lights for the 4×4 system are lit up,(both 4×4 and low range) but it is in 2wheel. It will not shift into 4×4.

About a week ago this happened but only lasted a minute or so, now its permanant.

With duck season starting Sat, not good!
Any ideas?

I had the same truck with the exact same problem so I feel your pain. Can’t help, though, because I never fixed it (it developed a rod knock shortly after).

The easiest solution as i saw it was to trade it in for a Toyota.

Good luck

Check your relay for the switch. If unsure, call a Ford dealership shop and ask them. They will generally give you a little free troubleshooting over the phone as to what to check.

I would suspect the 4×4 motor went bad on the transfer case ,have seen this happen and replaced a lot them at work

Jeff

Your vehicle has a transfer case shift position sensor that is located on the side of the transfer case. If the sensor is faulty, it will not know it’s 2 from it’s 4’s, it’s 4’s from it’s lows, etc etc.

The shift position sensor is round & located on the back of the transfer case with wiring going to it. The wiring splits into 3 connections that go to the ECM. Two 8 wire connections & 1 5 wire connection.

By measuring resistance at each circuit, a tech would be able to determine where exactly the fault lies. My guess would be that your problem would be electronic. If diagnoses reveals replacing the sensor is needed then I would assume your problem should cost you a few hundred at the most. Diagnoses is the key. A good shop should be able to electronically identify the shop in a short period of time.

The only exception I can think of is if a short in the wiring exist between the ECM & the transfer case. It could take awhile to locate the short. The wiring harness runs all the way from the transfer case all the way up into where the ECM is.

Good luck.

Is the Explorer a manual shift (lever on the floor) or electronic shift on the fly (ESOF) transfer case? If it’s a manual shift it’s more than likley the sensor on the transfer case. If it’s the ESOF transfer case it could be the shift motor, the transfer case shift control module, or a wiring problem. The first 2 run about $500.00 a peice and are usually non-returnable because they are electical parts. It may be cheaper in the long run to take it to a mechanic and have them estimate the repairs. This way you shouldn’t be held responsible if the diagnosis is incorrect.

Thanks for the tips, gives me some things to check.
But as luck would have it also blew a rear brake hose this weekend, so I’ll be spending a few hours under the truck tommorow.
After a couple hundred thousand trouble free miles, maybe its a sign of things to come.