Fuse that controls four wheel drive - 1999 Chevrolet Silverado 1500

SOURCE: transfer case fuse blows when engaging four wheel drive.

Hello;
Sounds like yoou have a short either in the switch pod or in the 4wd electrics. Check for pinched wires or bare wires grounding out at the front axle and at the transfer case.
Thanks;
Rich
RPM Northwest

SOURCE: Four Wheel drive not working. Blows fuses.

Hi:
Your four wheel drive push button system has only 3 components, so there is a way to narrow down what is blowing the fuse:

the system includes the push button panel and indicator light, the shift control module, and the shift control motor.

The shift control motor is the only part that can draw enough current to blow the fuse. If for some reason the transfer case is jambed up, that could blow the fuse too...So if you are planning on attempting repair yourself:

first, unplug the connector off of the shift control motor, and see if the fuse still blows.. if not, then remove the shift control motor from the side of the transfer case and plug it back in to the harness and see if the fuse blows. If so, then the shift control motor is bad, if the fuse doesnt blow then you need to check out your transfer case.

SOURCE: My 1999 chevy silverado 1500 four wheel drive

You probably have a bad encoder motor.It is located on the side of the transfer case on the drivers side.It is black.The other problem they had with these was the switch but you have already replaced this so your next thing is the encoder motor.Hope this helps.Good luck.

SOURCE: Four-wheel drive not working. No

Was the transfer case fluid changed every 50K miles? This very important on these trucks. The Transfer Case Control Module (TCCM) could be at fault, especially since you have no lights on the selector switch. Is the Service 4x4 light on? When you switch from 2H to any of the 4 wheel drive selections, do you hear any actuator noises coming from under the truck?