This truck (89 Dakota 2.5L) I bought has some mystery fitting and connectors. I'm sure I'll be back for the other ones but right now I'm mainly interested in the fitting below. It has two vacuum lines. The top one runs along the firewall to a fitting on the brake booster, and the one below it isn't connected to anything right now. I did just do a lot of work in the engine bay so it's entirely possible that I disconnected it at some point. I suspect it's part of the heater or A/C system but I can't find it anywhere in the shop manual. In fairness, the manual I have is for a 90 so this might be one of the small differences between the 89 and 90.



And here is a slight more zoomed out view so you can get a better feel for where it is in the engine bay.

 

Purge valve?? Where do the vacuum lines run off to?

 

Does the airflow run through the right vents when you change the indicator. Like does it go to the dash or feet or defrost when you set it to go there? Or does it see to be nondirectional? Anyway the flapper doors in the hvac box are controlled by vacuum it may be for that.

 

You have no vacuum diagram to refer to on this? I don't remember whether Chrysler did vac diagrams or not.

Steve

 

I have one in my '93 FSM.

 

On my 95, on the right side, facing the cab, a vacuum line comes off the manifold to a sort of F connector. That vacuum feeds the evap purge valve and the EGR. On the left side, a vacuum line feeds the reservoir, that feeds the climate control box, in the dash, and the cruise control. Also on the left is a line that feeds the MAP and, I think, the charcoal canister.

The climate control vacuum line goes through the firewall and hooks up to the HVAC control box. The HVAC box distributes the vacuum to the selected door actuators. If there is no vacuum to the box, it defaults to defrost mode.