Happy Sunday everyone. The title says it all.

I installed new lines under the hood from the intake to the firewall, but it looks like the transfer case vacuum actuator switch is allowing ATF into the system. 4x4 still works, but I imagine the switch needs replaced. I have found zero web discussions about a failing 4x4 switch affecting the HVAC vacuum system. Thoughts?

I bought a $10 heater/ AC control switch and AC and Heater Control Vacuum Source Hose Check Valve from a junkyard truck. No change and there's still hissing coming from the round harness connection behind the switch. Interestingly enough, there's an oily residue at the connection too. Once again, no web discussion about this.

Then it could be the panel mode door actuator under the dash that by default goes to dash and feet during a failure. Since it appears the dash has to come out, is the harness also worth replacing? (Not sure how reliable they are.)

Thanks.

 

Yes if there`s a leak, feet, defrost is the default mode. Also look behind glovebox

 

there is a blend door as well which I just ordered for my 1998 it is the problem I have