Part Time Light All Of The Sudden Coming On

[JWheeler331]

Here recently my Part Time light has started coming on. Usually when I take my foot off of the gas coming to a stop. 

Would this appear to be a vaccume issue? 

[Eagle]

On 7/5/2022 at 2:08 PM, JWheeler331 said:

Here recently my Part Time light has started coming on. Usually when I take my foot off of the gas coming to a stop. 

Would this appear to be a vaccume issue? 

 

Definitely.

 

You have the central axle disconnect on the front axle. That's operated by vacuum. There's a multi-tube vacuum harness that operates that, and it happens to be located right under the oil filter. Over time, drips from oil filter changes soften and destroy the connectors, resulting in vacuum leaks.

[JWheeler331]

On 7/6/2022 at 5:47 PM, Eagle said:

 

Definitely.

 

You have the central axle disconnect on the front axle. That's operated by vacuum. There's a multi-tube vacuum harness that operates that, and it happens to be located right under the oil filter. Over time, drips from oil filter changes soften and destroy the connectors, resulting in vacuum leaks.

Thank you. I replaced all of the upper vaccum hoses. I guess next up will be the lower ones. 

[Pete M]

another option is to shift the cab permanently and plug the vacuum lines.   there's a thread on it in the link in my sig.   

[gogmorgo]

Would lack of vacuum trigger the 4x4 light? I would expect it to be the opposite, no vacuum being no 4x4 light. But I could be wrong. 
The other likely scenario is the wire going to it is rubbed through and contacting ground.

[JWheeler331]

On 7/8/2022 at 9:46 PM, Pete M said:

another option is to shift the cab permanently and plug the vacuum lines.   there's a thread on it in the link in my sig.   

Pete, I am not sure what you mean shift the cab permanently. I have looked through the list several times but I guess I am missing it. 

[Pete M]

whoops, typo.    that was supposed to say "shift the CAD".  look under axles for CAD deletes.  

 

 

[boxyjeep]

I removed all the CAD vacuum junk and switched over to an electronic indicator switch on the transfer case.  Not too hard to do.

[gogmorgo]

7 hours ago, SoCalJeepComanche said:

I removed all the CAD vacuum junk and switched over to an electronic indicator switch on the transfer case.  Not too hard to do.

Is that just swapping in the switch from a non-cad transfer case? I’ve always assumed this could be done, but never tried it myself. 

[boxyjeep]

7 minutes ago, gogmorgo said:

Is that just swapping in the switch from a non-cad transfer case? I’ve always assumed this could be done, but never tried it myself. 

no, you need to run the wire and tap it in.  I did it.  Works well.

[gogmorgo]

4 minutes ago, SoCalJeepComanche said:

no, you need to run the wire and tap it in.  I did it.  Works well.

Do you not just plug in the harness for the non-cad tcase up at the firewall? Pretty sure that’s all I did when I went to an NP242, but it was a while ago. I just wasn’t sure if you could just just pull the switch out of a non-cad np231 and direct swap it for the vacuum cluster thing in the older 231.

[boxyjeep]

Just now, gogmorgo said:

Do you not just plug in the harness for the non-cad tcase up at the firewall? Pretty sure that’s all I did when I went to an NP242, but it was a while ago. I just wasn’t sure if you could just just pull the switch out of a non-cad np231 and direct swap it for the vacuum cluster thing in the older 231.

You might be able to do that.  I didn’t have a harness so made my own.