This is on a friend's truck.

2000 Chevy Silverado
4x4 with automatic transfer case
No codes, and no Service 4WD message

The selector switch for the auto 4wd lights up, however none of the selection lights do. (he's in 2wd right now and the orange light next to 2 Hi is not lit nor is any other).

I tried swapping out his selector module for my known working one, same thing. I tested the 4wd fuse and it tested good. I don't know what else to check for. I crawled under the truck and all the connections were good and tight, I tapped the actuator on the transfer case and for the front hubs with a hammer.

I'm wondering if maybe there is a bad wire between the module and BCM. Anyone else had this problem and been able to fix it? We've got snow just around the corner and he was hoping I could get it working before it hit.

 

Have ya pulled the actuator to see if it was moving

 

There are 2 fuses that you need to check. The 4WD fuse, and the ATC fuse(20a). If the ATC fuse is blown, sometimes the encoder motor is on it's way out, drawing too much current.

 

No, that's entirely too involved for a truck that isn't mine. I know the actuator isn't moving because when you push the buttons they do nothing.

I'll check this and post up results.

 

Blown ATC fuse.

Replaced it and had him change it in and out of 4HI back to 2HI a few times to be sure it didn't blow out again as soon as the encoder motor was enabled. Went through these few cycles without problem so hopefully he's in the clear. I let him know if he blows the fuse again it'll be that encoder motor giving him problems.

Thanks Roger, this is 2 beers I owe you for transfer case headaches.