I bought a 97 that had been sitting for a while. When I first got it I tried the 4x4 and could here the clicks and the light came on. Now no clicks and no lights. I unplugged the solenoids on the fire wall and checked with a test light with key on I have power but I checked for ground and did not have ground in any position of the esof switch. Does this mean it's the gem or is there something else?

 

It suggests the transfer case motor never operated to transfer the signal to the firewall solenoid.
Trouble is not operating the case motor to is't first position.
Good luck.

 

OK thank you, I will check there and work back, I was thinking the gem sent signal to firewall.

 

The GEM does send the signals to the firewall-mounted vacuum solenoids, but the transfer case motor position switches must first send the appropriate signals to the GEM before it will operate the vacuum solenoids.

 

I concur with the advice above, but want to add...

Are the solenoids good? Ford put them on the firewall in the path of water, which likes to infiltrate them. Then when winter rolls around the water freezes and they crack... poof no more 4x4. You'll know if they were both changed out because the "fix" replaces the stamped mounting plate with a plastic covered mount. I know because my 4x4 failed and it was the solenoids that had cracked. RockAuto had the best price by far on them.
Just wanted to share that as an FYI