94 Jimmy need help

[s15jimmy]

I have a 1994 Jimmy with 4.3 Vortec, 4wd.

My issue is the 4WD. The actuator under the battery tray has been replaced along with the switch on the T-case and Ive had new vacuum lines run from front to T-case. I can get it to go into 4wd, my issue is the vacuum will not release. When watching the actuator under the battery, the rubber diaphram is drawn up when locking in 4wd. When taken out of 4wd, the rubber diaphram does not relax since the vacuum is not released. In order to get it out completely, you have to remove the vacuum line off the actuator and then the diaphram relaxes. This is the first time I have dealt with a 4wd system like this, so I need to know if this is normal or what. Thanks in advance.

 

[Shane Mane]

Assuming that the new actuator and switch (encoder motor) on the transfer case aren't faulty and it engages 4wd but doesn't disengage, I'm guessing there's an issue with the wiring or in this case the actuator cable. The new actuator may be faulty though as it's not doing what it's suppose to do..

 

[Molson02536]

I have a 1994 Jimmy with 4.3 Vortec, 4wd.

My issue is the 4WD. The actuator under the battery tray has been replaced along with the switch on the T-case and Ive had new vacuum lines run from front to T-case. I can get it to go into 4wd, my issue is the vacuum will not release. When watching the actuator under the battery, the rubber diaphram is drawn up when locking in 4wd. When taken out of 4wd, the rubber diaphram does not relax since the vacuum is not released. In order to get it out completely, you have to remove the vacuum line off the actuator and then the diaphram relaxes. This is the first time I have dealt with a 4wd system like this, so I need to know if this is normal or what. Thanks in advance.

Check to see if there is still vacuum to the actuator, if it is then its a goof chance that the vacuum switch is bad at the transfer case.

Make sure your encoder motor at the transfer case is working properly and is disengaging from your 4WD, if so then its a bad vacuum switch still located on the driver's side on top of the transfer case.

Its a PINA to replace but can be done with a simple open end wrench.

Keep us posted
Molson02536