I recently bought a 1997 F150 so I would have a 4X4 during the few times we get snow. The 4x4 seemed to work fine while test driving it. But recently I tried the 4x4 and nothing... It's an electronic shift (Dashboard switch) type. 105k miles with the 4.6L.

I turned the dashboard switch to 4Hi and 4Lo, while moving slowly, while in park, while in neutral, etc., etc.

It doesn't engage, I don't hear anything, and the dashboard 4x4 light doesn't come on.

I should mention that it did finally once go into 4x4 Low and the dashlight did come on that one time. Since then I tried to take it out of 4x4 and the dash lights went off but it now seems stuck halfway between 4x4 Low and 4x2 as I can hear something spinning (whirring noise) and it shifts like it is still in 4x4 low.

I've read several postings and all seem to point to vacuum, solenoid, or an actuator. But all of those posts indicate the 4x4 dashboard light coming on. I've checked the solenoids and they definitely have vacuum as I can hear them bleed off if I unplug the lines. I tried swapping the 4x4 solenoid anyway and that didn't help. But since I am not getting any dash lights I suspect it isn't the solenoids/vacuum system anyway.

Does anyone have any ideas what the problem might be?


Thanks in advance!

 

Check the fuses for the 4wd system, there is a 10a fuse in the cab for the vacuum solenoids and there is a 30a fuse for the shift motor in the power distrobution box under the hood.

 

Check the sensor the shift sensor at the back of the t-case, pull it out and see if it is sticking!! that little sensor controls the dash lights and tells ur pcm that it is in 4wd

 

Thanks for the replies. I should have mentioned that I have already checked the fuses and all were good. I haven;t checked the shift sensor on the back of the T-case so I will do that next. Forgive me, but any chance you (or someone else) can give me some instructions on how to check the sensor. I'm "4x4 challenged" when it comes to this problem. I really have no idea what this sensor will look like or how to check it, or possibly un-stick it. Heck, even a link with a picture or sketch would be helpful!


Thanks!

 

Chances are the shift motor on the back of the transfer case is stuck. THe contact points in the motor get corroded and stick, preventing the motor from engaging. Have someone turn the **** on the dash from 2wd to 4wd back and forth with the key on and the truck NOT running. Crawl under the truck and use a hammer and tap on the shift motor unit. If this works, then you may get some more use out of it for a while, but the shift motor will eventually need replacing. They go bad from non use in the summer. You should periodically engage the 4x4 so the motor is activated to prevent it from sticking.
Also check at the lead going to the motor for power. The control unit in the dash do go bad, but very rarely. WE've sold alot of these shift motor over the years.

Barry

03 F-150 reg cab 4x4
( Ford parts man )

 

This sounds like one of those cases where the GEM is not working. The GEM turns on the light. Check the Central Junction Box in the cab for sign of corrosion. The gen is screwed to the back of the fuse panel and water intrusion from a leak in the windshield causes all kinds of problems. You should test the switch just for good measure. Probe the resistance between the two dark blue wires on the switch with the connector removed. In 2Hi there should be 3.9K ohms, 4Hi should read 1.1k ohms and 4Lo should read 360 ohms.

JMC

 

I'm trying to track down the same issue. One thing that I'm getting that you didn't mention was 5-6 distinct clicks behind the instrument panel when the truck is first started. I've tried disconnecting the vacuum solenoids, and even ran jumper wires across the terminals to permit the current to continue, but I still have the clicks and no dash lights.