More on The Cruise Problem

[MJWenrich]

In July I posted the problem with the cruise vacuum module behind the passenger battery. Replaced that because after plugging all the lines it continued to run. But....the new module still runs. After tracing back and blocking the line that crosses the engine and connects to the module under the drivers side battery, I still had a leak. So I disconnected where the line tees into the interior of the dash. The unit then stopped and now I cannot determine where that line goes. My Haynes manual does not cover that and I don't know if I have to remove the dash or just some other smaller part. Like the glove box.

Anyone have any ideas where the line is going? I suspect a vacuum module for the A/C but everything on the A/C functions.

Also, I ignored the constant running of the Dorman module I replaced thinking it was something else (maybe fuel pump) because everything was functioning. For about one year. That probably killed the shutoff on the unit.

 

[cerberusiam]

What doesn't work inside, if anything? I wonder if there isn't a vacuum reservoir under the dash or cowling to help minimize duty cycle. AFAIK, all the controls are electric in the 3rd gens and only the first 2 years needed vacuum for the CC only.

 

[MJWenrich]

Everything works now and the only thing that does not work is the cruise because I have the pump I replaced disconnected. That is what puzzles me the most. There must be some need for vacuum inside the cowl as the line from the pump travels across the engine down to the servo and right above the valve cover there is a tee where it goes inside the cowl. Some where in there it seems might be the problem as I disconnected the line at the servo and it made no difference but when I disconnect at the pump I can put my finger over the outlet and stop the pump. The tee is a rubber connector to the plastic line and I cannot seem to disconnect any of those three connections. The rubber is possibly sealed to the fitting.

When the electric is connected to the pump, the cruise works but the unit does not shut off. So the leak is just bad enough to keep it running but not so bad that it disables the cruise. I can't determine where that line goes from the outside without dismantling the dash so I was hoping for some idea about what it does in there.

 

[MarkEagleUSA]

I can't determine where that line goes from the outside without dismantling the dash so I was hoping for some idea about what it does in there.

I found this in the service manual8P-10)

The vacuum reservoir is located in the engine compartment
under the fresh air cowl grill panel (Fig.
12).
(1) Remove wiper blades and arms. Refer to Wiper
Arm Removal / Installation in the Wipers / Washers
section.
(2) Remove fresh air cowl grill. Refer to Cowl Grill
Removal / Installation.
(3) Disconnect vacuum line at reservoir (Fig. 13).
(4) Remove 2 reservoir mounting nuts (Fig. 13).
(5) Remove reservoir from cowl.

 

[MarkEagleUSA]

Then I see this:

DESCRIPTION
The vacuum reservoir is a plastic storage tank connected
to an engine vacuum source by vacuum lines.
A vacuum reservoir is not used with diesel engines or
the 5.7L gas powered engine.

 

[MJWenrich]

Thank you Mark. I am going to look in that area anyway because maybe the cowl entry/exit for the line will give me a clue. A faulty reservoir would make sense too.