No A/C in 4x4

[docchiro08]

Weird issue....if I have my A/C on and put the truck in 4x4 it automatically switches A/C to defrost and blows vent air instead of cool air. A/C and 4x4 otherwise work fine. Is this still an issue with the vacuum lines and if so, is there a specific line to check that would cause this? If not, where should I start my search to fix this? Thanks

[jesilvas]

Vacuum. Check lines going to front hubs. See if the vacuum pump even works.

[docchiro08]

Thanks, I'll do that! Kinda figured it might be vacuum lines, but nothing I've read had exactly the same problem as mine

[maddogv21]

I had a autohub $hit the bed so I just installed Warn lock outs. vacuum issues no more!! plus the vacuum actuator was junk. so I just bypassed it and ran the vacuum from the venting to the vacuum box. Works like a charm now.

[bboysen]

I had the same problem with mine a while back. This is what I did:

I started with the hubs and found that both of my lines were broke so I replaced them. Then I when in to the engine bay and found the vacuum lines on the passenger side fender wall. On the bottom of the vacuum actuator there are two lines coming off of it. One runs in to a t and then in the canister. The other one runs south to a t on the frame rail and then to your hubs. I could almost bet that there is a leak between your hubs and the actuator or your actuator is bad.

I took the two lines off of the bottom and plugged the bottom one (this is the line that runs to your hubs) with a rubber glove that i had in the truck, waited about a min or so a boom I now have ac coming out of the vents not the defrost. I hope this helps here is also a picture of the vacuum actuator.

[docchiro08]

That's awesome! Very detailed response and very helpful. Thanks alot bboysen!!