Carcrazygts2

If your gem was bad it means your front windshield is leaking.

MCpllabelle

I second that conclusion.

Project_Red_F150

Just because his GEM was bad doesn't mean his windshield is leaking. 99% of the time when something electrical goes bad there's a shortage somewhere. I have a separate switch for my fan in my 97 F150 and I hooked it up all weather proof and I got a bad connection because it shorted out. So his GEM had a shortage somewhere just like mine

white89gt

Ummmm, more like 99% of the time a GEM issue is the windshield leaking.

Jason White

Hi, Austin 97 I have been reading through some of these old threads as I'm having trouble with my 4x4. You seem very knowledgeable on this subject. If you are still active on here I'd like to talk with you a little.

Jbrew

Great that you researched! It's better to post a new thread at this point. The problem and what you've learned and done about it so far. That way you'll get a few folks to expand on the issue....share their experiences.

Jason White

Thanks

Jonathan Clark

IMO; I do know the back window is notorious for leaking, i havent had one that hasnt.. and sometimes when i buy em there's condensation built up on the windshield alot of times...

im not saying water didnt cause the issue, just curious as to where it might actually be coming from

Datarin

I've having similar problems I've tried swapping gems but that mad it worse....
right now if i turn my key on the relay in the dash clicks ll6 times then stops and I can't go into 4x4. I have power to the 4x4 solenoids but no ground to the 4x4 solenoid. All fuses are good only codes my scanner pulls is the switch shift motor and a wheel speed sensor from the gem.

Bluegrass

Problem is.............. few take the time to learn how the 4x4 system works.
Switch request from the dash for 4h tells the GEM to operate the case motor to it's first position by powering the relay.
If the relay does not come up, the case motor will not run.
If the relay does come up and there is no power to the contacts the case motor will not run.
If the motor is faulty it may not run.
.
If the case motor does go to first position, a ckt board set of 'wiper' contacts closes signal ground to the fire wall solenoid, operates the solenoid and causes the 4h dash lamp to come on. In turn the solenoid applies vacuum to the front Actuator sliding a splined collar to lock the passenger side CV axle halve to gather. If the case circuit does not cut through to the fire wall solenoid or the solenoid is stuck, the front will not lock up
Your job is to see where the operational failure occurs.
Is it fuses/
Is it a faulty case motor? Is it stuck in first position? The case motor also turns a shaft in the transmission to engage the case gearing.
Is it a faulty GEM?
Test and verify the last part of the chain to fail and what is supposed to happen.
Yes the early trucks have a leaky windshield issue as the GEM is right in a position to get wet.
This can also cause random uncontrolled operation and failure as well.
Be sure the plugup at the case motor is clean and good.
.
As to 4L, the truck has to be stopped, foot on brake and shifter in Neutral.
Only difference is the case motor runs to a second position, dash lamp lights 4L, case gear reduction takes place and the computer is signaled to use a different throttle response program line.
When the dash switch is returned to 2wd, all functions reverse. The case motor is a DC motor so responds to turning in reverse when the relay applies reversed polarity power.
None of these functions has anything to do with the rear axle.
.
Follow the function sequence and see where it fails and only work on that part of the system.
Good luck..