I have a 99 F250 Super Duty with the Triton V10. The ESOF 4x4 is not engaging. I have Jem part # F81B-14B205-DJ Version D. I am not sure if it is the stock Jem, I bought the truck used and the previous owner had the truck worked on and I am not sure what was done in the past. The 4x4 light is the cluster works for a second when i start the truck but does not light when i turn the switch. I put a test light and meter on the two prong plug that connects to the solenoid motor on the transfer case and have no power there. I do not hear any clicking from the relays. The Egr vacuum solenoid is also not working but i am not sure if that would effect the transfer case from engaging. Does the transfer case require vacuum to engage. I have no problem with the EGR vacuum not working if it only effects the heating system, I can deal with heat being on defrost and will keep the hubs in the lock position but if the egr vacuum efects the way the engine runs or assist in engaging the transfer case I will replace it.

What I need to know is if i have the proper jem for the truck?

How do i test if the relays are being powered?
What color are the wires or wire # coming out of the jem for the ESOF.

Thanks for looking
SM