4x4 low wont engage

[RonD]

I would say GEM issue then

 

[Jaspers73964]

I am going to get one ordered and swap it out. I will update once I swap it out. Thank you for all the help!

 

[Jaspers73964]

Update - I have replaced the GEM module with a refurbished unit and have the same results. No low range, and dash lights still do not illuminate when turning the key on. Any other thoughts to what could be the problem?

 

[dvdswan]

Are the pins in the connector making contact with the module pins?

 

[Jaspers73964]

Yes, all pins are fully seated in harness connector. None look to be flattened or bent

 

[Jaspers73964]

I checked the contacts on the clutch pedal, 2 center pins have continuity without pedal pressed, outer contacts have continuity when pressed. I checked across all pins and made sure I didn't have continuity on pins that are part of the pairs.

 

[dvdswan]

Well, it is possible the replacement GEM is bad. I'd hate to send you down a rabbit hole since @RonD is (I would imagine from his knowledge in posts) a technician or even a Ford technician.

I was about to say check the continuity, but you've just posted that.

 

[Jaspers73964]

I would suspect other issues if replacemet GEM was bad. Only reason I say that is the symptoms mine is showing are not common with other posts I've read. All of the issues I've read have other problems along with it. Unfortunately mine seems to be different. The replacement GEM is doing the exact same thing as my original. My mind is fried trying to figure this out lol.

 

[Jaspers73964]

I can't help but wonder about the speed sensor input. Could my ABS and speedometer work properly but not show that the vehicle is not moving for the GEM input?

 

[dvdswan]

Anything is possible with electronics.

 

[RonD]

In 1998-2000 Rangers the GEM is the speedometer

In the 2000 4WD diagram
The GEM will GROUND the Gray wire to light up 4High, and the light blue/black wire to light up 4Low
You can ground each wire to test if bulbs work, key on

This wouldn't effect shifting in any way, just tell you if bulbs are OK

 

[Jaspers73964]

I have done the bulb tests and both indicators work on the gauge cluster.

This evening I messed around some more to try and figure this out. I grounded connector 17 (brown pink) for the ccw relay and the transfer case went into low range, but no light on the dash which I expected since I'm bypassing the GEM. I then grounded pin 16 (grey) to energize the cw relay and the transfer case went back to 2H and stopped. I thought it was odd that I cannot ground pin 16 from 2H and make it go into 4H like I can with low range. Im not dwelling on that because 4H works without issue. I can use the 4x4 switch to go into 4 high and dash light illuminates as expected.