When I turn the swith on the dash to 4 x4 will not engage
The 4x4 light only come on when you start the truck and then goese out .
Which is normal
The fuses are all good
I get power to the 4 wheel drive module.
Open the module up there was Crousion on the board
So I check the 4x4 relay box found a problum I only get power the to the relays from. 87A and I'm showing ground on 85. 86
This seems to be the problum what should I check next
The wireing diegram I have shows power should be on
86. 87
I have cleaned all the connectors and don't see any broken wires yet
I plan to remove the the transfercase slector and motor to see if there is any thing rouge on the rang slector

 

I don't show those relay numbers in the info that I have.Where was this relay mounted?
Where did you get that wiring diagram?

 

After checking everything I replaced the control module and the. problum was fixed this is a problum on 2002 and 2003 models only . The module. Is located behind the glove box it is black and has three gray conector going in it . To you can see and one you can not untill you pull it. If you neeed to check you relays thay are under the hood on the drive side next to the fire wall . The box has 5 relays and two fuses in this box. Only two relays are the 4x4 relay