I have done a fair amount of research on this, but I am stuck. I have a 1999 jimmy with the 4 switch 4WD buttons including auto. I cannot put it into 4WD. Here is what I know:
1. I have the 4WD with the two wire actuator on the firewall that controls the vacuum. I have included a picture of this switch.
2. When I turn on the ignition, the service 4WD light comes on and then goes out. The lights for auto, 2wd and 4hi also light and auto and 4hi go out. 2hi remains on.
3. The light for 4Lo never comes on.
4. Fuses are fine. I have pulled both the ATC in the engine and the 4WD fuse in the interior for 30 seconds - no change.
5. The vacuum actuator under the battery is working when I bypass the vacuum switch on the firewall (connect the two hoses that go to the switch) and the cable seems to be being pulled properly. However, even with vacuum applied and the cable pulled, I am still not in 4wd.
6. Pushing any of the buttons currently does nothing, either stationary or moving. Hi2 stays lit. A couple of days ago I pushed auto4wd and it seemed to do something, but then the service 4d light came on in the dash. It has not come on since then, nor does the auto 4d button appear to do anything.
I thought that you could engage 4wd by pulling on the cable, and in fact there were manual locking cables to replace this system, however it appears that even with the cable pulled I do not have 4wd.
There appears to be a lot of information relating to the non auto 4wd transfer cases that has confused me. I tried to get my vehicle on ramps today to look at the transfer case, and could not because the grass was wet and I had no 4wd. I am not sure if my vehicle has the three vacuum line switch in the transfer case and whether that would be relevant to this situation.
Any thoughts, suggestions, or advice would be most welcome.
1. I have the 4WD with the two wire actuator on the firewall that controls the vacuum. I have included a picture of this switch.
2. When I turn on the ignition, the service 4WD light comes on and then goes out. The lights for auto, 2wd and 4hi also light and auto and 4hi go out. 2hi remains on.
3. The light for 4Lo never comes on.
4. Fuses are fine. I have pulled both the ATC in the engine and the 4WD fuse in the interior for 30 seconds - no change.
5. The vacuum actuator under the battery is working when I bypass the vacuum switch on the firewall (connect the two hoses that go to the switch) and the cable seems to be being pulled properly. However, even with vacuum applied and the cable pulled, I am still not in 4wd.
6. Pushing any of the buttons currently does nothing, either stationary or moving. Hi2 stays lit. A couple of days ago I pushed auto4wd and it seemed to do something, but then the service 4d light came on in the dash. It has not come on since then, nor does the auto 4d button appear to do anything.
I thought that you could engage 4wd by pulling on the cable, and in fact there were manual locking cables to replace this system, however it appears that even with the cable pulled I do not have 4wd.
There appears to be a lot of information relating to the non auto 4wd transfer cases that has confused me. I tried to get my vehicle on ramps today to look at the transfer case, and could not because the grass was wet and I had no 4wd. I am not sure if my vehicle has the three vacuum line switch in the transfer case and whether that would be relevant to this situation.
Any thoughts, suggestions, or advice would be most welcome.
