Did the basics lick vac and vss switches. Madd Relay is not picking up when you shift into 4x4. Even if the light does not come on the dash shouldn't the Relay click before the vss switches change vac on the actuator?? Running out of ideas and any help would be great.

91 Toyota 22re 5speed with ADD already searched and found basic tshooting steps but still having issues

 

There is a switch on the transfer case that detects when you shift into 4wd. That switch closes a circuit to ground and switches the output of the ADD relay from the 2wd VSS to the 4wd VSS. If the relay isn't clicking then that switch could be bad.

 

try tapping on the front actuator w/ a hammer when shifting it. with the truck off the ground. have fixed many this way.

 

Thanks guys i will try that this weekend. will keep you posted