I'm having problems with ESOF on my 99.5 F350 .I have checked fuses and conections but no light on dash and no four wheel drive. What relays are there to check and how can you test them,where are they located? How do you get the switch out of dash? Thanks for any help................

 

The switches will come out of the dash if you pull the dash trim around the radio and gauge cluster. I am not 100% sure if the light will go out if the vacuum lines are an issue, but there is a vacuum pump that engages the hubs, and the vacuum lines go bad all of the time. Check the vacuum lines, and the vacuum pump, as the pump goes out a lot as well. My Brother-In-Law had this problem in his. One way to check is to turn your heat on and shift into 4X4, if the heat defaults to defrost, you have a vacuum issue. I have not heard of a lot of people losing the electric switch, but it is possible. Just my $0.02.

 

Got a new transfer case motor at Napa ,that was the fix..........

 

What was the Napa part # .... it may help someone down the line.

 

I gotta ask, how in the heck do you go from not knowing what is wrong to fixing it with a new transfer case motor? How did you figure it out so quick?
Joe

 

Tcm 48-205 is the Napa part # remanufactured transfer case motor

 

Searched alot of forums from different web sites .Most everyone said auto hubs and transfer case motor were the weak link in the ESOF system.My hubs aready went south so I keep them manualy locked for winter, so I went for the motor. My driveway is down a hill and a f350 dually without 4 wheel in snow is an anchor...ha ha ..I was desperate Joe.