4x4 not working?

1997 CHEVROLET 1500

268 MILES • 5.7L • V8 • 4WD • AUTOMATIC

BRANDON5.7

MEMBER
1 POST

I have electric 4x4 push button on the dash. I’m getting 12volts to my front differential. And only 3volts to the speed sensor on my transfer case and I’m not getting any power to my 4x4 actuator on my transfer case. My 2hi option on my dash only comes on when I turn my headlights on but it’s a really weak light. Would this be a bad ground. All the ground are connected on my truck. And if it is a bad ground could I add another ground location off of one of my transfer case bolts to my frame?

May 27, 2023 at 10:24 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

I would check the power and grounds to the transfer case control module, and if all good replace the module, here is the location of the module and the transfer case wiring diagrams and a guide to help you with the testing.

https://www.2carpros.com/articles/how-to-check-wiring

This guide may help as well:

https://www.2carpros.com/articles/in-depth-guide-diagnosing-and-repairing-automotive-transfer-case-issues

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

May 30, 2023 at 9:52 AM