Will not come out of 4low

[Rustypos]

Hi All,

Hoping for some help here. Pickup is stuck in 4low. 4high and 2wd buttons flash but will not switch over. I’ve checked fuses, disconnected the battery and tried every variation of cycling through neutral, drive and reverse while pushing 4high to “unbind” it.

What’s the most logical next step? The dash switch itself or the actuator? I’m a YouTube proficient mechanic so any advise is welcomed. Thank you!

Truck is a 1997

 

[351FUN]

Smells like the actuator to me. You can test the switches/buttons easily with a meter, take all contacts off and measure resistance. Should go from open to something low, 0.5Ω or less when you press it. If you have 12v control power and functioning buttons, the next step is the actuator.

 

[ima93chevyguy]

Actuator is usually the culprit.

I have a GMT800 and it fried the actuator and the 4wd computer, had to replace both. Not sure if these trucks have a computer for it as well or not.

 

[Rustypos]

Thanks for the responses and happy Easter! I’ll have another look this week and report back what the fix was (hopefully)

 

[Harry Dawg]

Second actuator. It's a fairly easy part to replace.

Also check the connector coming off the wiring harness to the transfer case.

I had a situation where the transfer case came unplugged while I was four wheeling and it did the exact thing you are describing.

There is also a transfer case control module that sometimes fails.