S-10 Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
309 Posts
Discussion Starter #1
went to put it in 4x4 - 4 hi on the weekend and the light would only blink, it wouldn't stay lit up...

wouldn't switch back to 2hi, but it would just keep blinking at 4hi?? not sure if it engaged or not, but i didn't want to get stuck and find out...

once i pressed the 2hi button, it would switch back to 2 hi, and light would remain lit... but when i pressed 4hi, it would only keep blinking???

any ideas?
 

·
Registered
Joined
·
4,257 Posts
Vacuum lines, vacuum actuator, or encoder motor.

These are a few of the common causes of the symptoms you are talking about.

Vacuum actuator is a rubber diaphragm located under the battery.
Encoder motor is the little motor that attaches to the transfer case.
 

·
Registered
Joined
·
139 Posts
I actually have had that problem twice and I just unhooked my battery overnight and it solved the problem. Dont ask me how but it worked.
 

·
Registered
Joined
·
4,257 Posts
I actually have had that problem twice and I just unhooked my battery overnight and it solved the problem. Dont ask me how but it worked.
This is a solution for when the encoder motor screws up. I found that it is very easy to confuse the encoder motor if you get to hitting buttons too fast. Resetting the computer clears everything out but you do have to leave it unhooked for several minutes.

If it still doesn't work after you do this, the encoder motor is not your problem.
 

·
Registered
Joined
·
928 Posts
Aside from the battery, a new 4x4 switch is the next cheapest to replace and is easy to test. Not usre if you have a 3 button or 4 button but they are cheap on eBay. (paid $.99 plus a few bucks shipping for my 4 button)
 

·
Registered
Joined
·
54 Posts
Check the vacuum lines right around/behind the brake booster.You should see them pretty easy.There is a t-fitting.The small vacuum line on mine was dry rotted and had split so there was no vacuum in the system to activate the 4 wheel drive.Also check the actuator under the battery.Sometimes they go bad or the vacuum line to it may be rotted and split.Hope this helps.
 

·
Registered
Joined
·
3 Posts
I would start with the vacuum lines. They are the easiest to check. I just went through this on my 99 Jimmy. They were very dry rotted at the T connectors that were mentioned above. I replaced all of these lines and now it works very quickly. I hope this helps.
 

·
Winter Projects....
Joined
·
141 Posts
Ok, I replaced the actuator, and all the vacuum lines, and the switch on the case. I really wanted to drive it so I took off the encoder motor, put the truck in neutral, then switched it into 2wheel drive with a wrench.

Must the the motor right???

Is there a good way to test the thing before I go and spend a leg on a new one?
 
1 - 11 of 11 Posts
Top