4X4 will not engage?

Tiny
TCOON1998
  • MEMBER
  • 1995 GMC YUKON
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 107,000 MILES
I have the vehicle listed above with the 4x4 stick on the floor and when I try to shift it into 4x4 nothing happens; no dash lights or anything. Can someone please help me with this? I’ve only had the truck about 2 weeks.
Monday, March 24th, 2025 AT 9:20 AM

11 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Hello,

The first thing you need to do is check the fuses: illum, and 4WD in the fuse panel under the dash.

This guide can help you:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Here are the fuse locations and the 4wd wiring diagrams which should help as well. Check out the images (below). Let us know what you find.
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Tuesday, March 25th, 2025 AT 2:50 PM
Tiny
TCOON1998
  • MEMBER
  • 6 POSTS
I’ve checked all the fuses and they’re all good so what’s next?
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Tuesday, March 25th, 2025 AT 3:31 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Most of the time it will be the front axle actuator, but I would use a test light and check the lt-blu wire for power when the system is on.

Here is a guide to help:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is the location of the actuator so you can check it out, if it is getting power check the ground as well and if good replace the actuator. Check out the images (below).
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Thursday, March 27th, 2025 AT 8:13 AM
Tiny
TCOON1998
  • MEMBER
  • 6 POSTS
Alright, I’ll check that when I have the chance and post an update, I really appreciate it.
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Friday, March 28th, 2025 AT 6:12 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
NP, have a good weekend!
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Saturday, March 29th, 2025 AT 10:30 AM
Tiny
TCOON1998
  • MEMBER
  • 6 POSTS
Will any 4x4 lights come on if the encoder motor is bad? Because nothing happens when I try to put it in 4x4 no flashing lights or anything.
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Friday, April 4th, 2025 AT 6:44 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Did you check the fuses for power as in the guide above? Also, I would check the ground for the system which is at the G119 right front of the engine.
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Friday, April 4th, 2025 AT 10:33 AM
Tiny
TCOON1998
  • MEMBER
  • 6 POSTS
I haven’t checked the fuses for power yet I work a lot and I’m trying to do it when I get some time off, but another question is also the shifter for the transfer case has no tension in it. What would be the cause of that?
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Tuesday, April 8th, 2025 AT 5:53 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Hmm, it sounds like something might have broken, or the linkage has come off, have a helper work the lever as you check the transferase linkage, here is what it should look like.
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Wednesday, April 9th, 2025 AT 10:53 AM
Tiny
TCOON1998
  • MEMBER
  • 6 POSTS
I have discovered that where #2 fuse goes the prongs inside that holds the fuse are broken so how do I go about fixing that? Do I have to replace the whole fuse box, or can I just replace the one fuse line?
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Wednesday, April 9th, 2025 AT 3:39 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
It does not look like a fuse goes in the #2 slot of the fuse panel?
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Friday, April 11th, 2025 AT 9:49 AM

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