The Transfer case shift relay module is located behind center of dash. There is a relay in the rpo block under the oval cover of dash that is 4x4 related . try to reset gem. unplug battery for 10 minutes and hook it back up. see if that changes anything. you need to check switch also. The tcscm is what runs the transfer case motor. the rpo relay handles the syliniods

 

Ok thats the only thing I didnt check is the relay module behind the dash.

Do you know how to get to them? I remember looking back there and seeing nothing but air ducts.


Thanks for everything Hawk

 

The pic i have, it looks like its mounted to the bar going from door to door right behind stereo. The click i hear in my truck sounds like it is deep in dash behind vent that is between gages and stereo.

 

Ok I found a module with the part # F85B-14B194-CA.

I believe its the one but I though it would be a couple relays from what ive read.

How do I test this thing? I cant find a diagram that shows what wires goes to it.

 

Id back track wires from tc motor and check for power. locate wires going to gem and look for signal when switch is switched. it should also have a power wire coming from power distribution box. i have no schematic of it. i would have to figure it out.

 

That f85 number sounds like the gem number. Are you sure it is for the relay module.

 

That part number is for a transfer case shift relay module. You found it.

 

Found a pretty good link to help me in testing,check it out.

http://www.justanswer.com/uploads/mu...22418_1121.pdf

 

My question now is if the relay module is bad,what other vehicles can I find them in? My local junkyard rarely has any 4x4 f150 or expeditons.

 

I cant answer that one. sorry. good luck. let us know what you find out

 

Good news Hawk I fixed it!!

It was a corroded wire(DG/LG) coming from the distribution box under the hood.

Thanks for everything guys.

 

FYI...
The relay module is located in the dash to the upper right edge of the instrument cluster. The radio/hvac bezel will not provide access because of the vent duct behind the bezel nor will you have access through the oval. You must first remove the dash panel above the steering column and below the instrument cluster by simply prying it off with your hands. Then, turn on your headlamps and pull on the **** until it pops out a bit for the fog lamps. On the back of the **** you will find a tiny opening, insert a small precision screw driver and this will free the **** for removal. Turn the **** 180° and reinsert it. This will be your tool for removing the headlight switch component. Once the headlight switch is out of the way you must remove all the bolts, 9/32" will work, don't forget the bolt behind the headlamp switch and the three above the instrument panel and the remove cluster surround panel. Now the relay is accessible, no need to remove the cluster itself. It looks like it's mounted to the bottom of the dash, but it's not, at its highest most point to the upper right of the cluster. First remove the electrical connection then firmly grab the module and slide it towards the cluster while lifting the release tab up that is located on the bottom of the module, walla! Good luck!