Replaced the GEM for a second time. Don't have power at either FWD vacuum solenoids. Have checked fuses. Research says ground returns to the GEM

Where does the power come from for the FWD solenoids?

-Mark..

 

Hot wired the FWD vacuum solenoid today and the FWD engaged. So the problem is definitely is no power to the solenoid.

Does anyone have a link to the 4x4 drive schematic?

-Mark

 

Does this help?

https://www.f150online.com/forums/vi...diagnosis.html

 

GLC,

It has indirectly helped. Fuse 23 was not blown, but in reading its description, in the manual it connects to the RPO relay. I have located the relay block under the dash but now have to determine which relay of the 4 is being used by the FWD solenoid.

-Mark

 

glc,

It has helped indirectly. Fuse 23 was not blown, replaced it anyway, no change. In the owners manual it states fuse 23 connects to the RPO relay. I found the relay block the RPO is in. Now I have to figure out which of the 4 it is.

-Mark

 

The owner's manual should have fuse and relay locations and identification.

https://www.fordpro.com/en-us/fleet-...ls-and-guides/

 

The RPO relay block is under the "oval" on top of the dash. I should be receiving new relays tommorrow.



-Mark

 

New relay fixed no power to the FWD solenoid.

-Mark