Question about 4wd
Administrator
Joined: Apr 2010
Posts: 87,380
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From: Clayton MI
Mechanical linkage to shift the t-case, vacuum locks the CAD, that's all. Make sure you are getting vacuum to the t-case. The old style switches are notorious for corroding, and seizing up....
Record Breaker
Joined: Sep 2010
Posts: 1,743
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From: Parker, SD
Thanks again! I got to check the vacuum lines from the CAD. The two from the CAD go to the transfer case. Then I found there are four lines that enter or exit here. No smoke from anything between the CAD and transfer case. There were two lines that are in the protective plastic that looked like they did go up to the engine compartment. One of those I think is one that provides the vacuum for the system and one that appears to be a vent terminating near the distributor. Not sure if I'm correct on the routing though. The transfer case definitely locks into 4L and 4H. So I am guessing the vacuum part is good. Hopefully tomorrow I'll have some help and will try dodgetruck2 method of testing the circuit by unplugging and jumping the pins. Does the transfer case need to be in 4L or 4H to do this check? And if I do get a dash light, can I assume it's the sensor? As always thank you for all input.
You have your vacuum source from the intake down the the t case, 2 lines to the cad actuator and the line back up to your "vent" is actually the vacuum inlet filter. remember when working with vacuum everything is pulling towards the intake, not pushing out the exit
Administrator
Joined: Apr 2010
Posts: 87,380
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From: Clayton MI
Veteran
Joined: Jul 2017
Posts: 264
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From: Rich Square NC
Mines a 96 2500, when I pull the lever the light takes a second or two to come on, according to both my sun visor AND my owners manual I can go in 4 High at any speed up to 55, 4 lo, I stop, place the trans in Natural engage 4 low, wait for eth light put it in 2 or 1 and drive slow
