2005 manual 4wd select has no power to fuse

[edwarrdo]

I’m working on a friend’s 05 single cab, it’s a basic package with vinyl floors and what not. Automatic transmission and a manual transfer case. Last winter the 4wd worked fine and this winter the front differential won’t engage.

The transfer case switches into 4H or 4L just fine but no luck on the front diff. I’ve checked the ground under the drivers door, have a good ground and tested it at the actuator on the front diff. Tested the brown and blue wires and no power from either whether in 2H or 4. Checked fuse under the hood and inside the driver door.

Pulled the fuse inside the driver door and tested and there is no power coming to it at all.

From what I’ve read, the brown wire on the front diff actuator should have constant power with key on, and blue wire should have power in 2wd. I’m not getting either of those.

Anyone have any idea why I wouldn’t have power at the in-cab fuse whatsoever?

 

[dndj]

Brown wire on the axle actuator is powered with key on from the 4WD fuse in the left side dash fuse block as you said.

The blue wire on the axle actuator supplies ground to the axle actuator when the shifter is in 4WD mode. In 2WD, I suspect you would measure 12v on this wire due to resistive pullups in the ECM or EBCM.

The 4WD fuse is fed from the 40A IGN A fuse, through the ignition switch. If that 40A fuse was blown, a bunch of other stuff wouldn't work. Power from the ignition switch to the 4WD fuse enters the left side dash fuse block on connector C2, pin A. Should be a large orange wire. Check for +12v there with the key on.

 

[edwarrdo]

Thanks for the information, I’ll get it back in my shop this week and I’ll post what I find.