flashing 4x4 light on 96 suburban

when I try to shift into 4 wheel high the indicator light on the butto keeps flashing and it never engages, what could be the problem??

Yeah when my Suburban did that it turned out to be the thermo actuator on the front diff. Easy fix, pull the wire off of it and engage the 4x4 switch see if you get voltage........if you do pull the actuator and put a ground on it and 12 volts to the blue wire the needle should start to come out if it does not you need to replace it.

Brian

If your thermo actuator turns out to be bad you might want to consider replacing it with an electo-mechanical one. The thermo actuators are a known problem.

Do a Google search for TSB#76-43-01A

I switched it into four whhel drive and checked the connections but had no power at any of the wires. I raised the truck off the ground and switched it into 4x4 and noticed the front driveshaft was spinning so it has to be the actuator on the front diff like you said but I cant figure out why I have no power to the wires. Is there a way to jump it or could that damage something? I have no wiring diagram so if anyone could tell me what wires are what it would help alot. Once again it is a 96 Suburban LS 4x4.

If you want to send me your email address I'll forward the wiring diagram to you.

The blue wire should have had power with 4x4 selected and key on. Check 4x4 fuse in the interior fuse panel. From the 4x4 fuse power is on a brown wire to the transfer case switch(on top of the transfer case, drivers side above and behind where the front driveshaft is). If you can remove the connector from this switch, check for power on brown wire(ign on, should have power whether 4x4 or 2 wheel). If you have power to the brown wire and no power to the blue at front axle, you should replace transfer case switch and I have heard they cost about $30

where can I buy the transfer case switch??