Vents won't change and I'm stumped

[kozy]

I recently bought a 2000 GTP with dual climate control and the vents are stuck on a mix of 80% floor and 20% main vents. I've searched for what to do and pulled my glovebox off only to see this. Am I missing something or is there no vacuum hose coming off the top of the round thing in these pictures???

[Scottydoggs]

on the top of the supercharger is a vac line that runs to the fire wall, make sure its hooked up. it powers them pumps.

that line runs down the pass fender under the fuse box then into a wire harness into the car.

[kozy]

Yea that line is in place. Don't see any blatant breaks in the line at all before it enters the wire loom.
I thought that same vac line connected to the round device in my pictures though.

[Scottydoggs]

those yellow lines are air lines.

that line you followed comes into the car under the fan, then to the console area. the cc its self maybe bad, or the box in the console.

you can try to move the linkage off the them two pumps by hand, dont forrce them to move, the linkage is plastic and can break.

[kozy]

Replaced the vac line coming off the supercharger and didn't fix the problem. Sounds like it's time to start replacing other things under the dash

[Iceman6669]

Mine was the same way when I got it. The line had a small break in it down by the battery.

[komrad36]

Pull the line off the vac/elec control module and see if you feel/hear vacuum when the car is at idle? If not, that's likely the problem. If so, it may be that vac/elec module itself. Another test is to then select a different mode on the CJ2 and listen for whether you hear relays clicking in the vac/elec module.

Komrad36

[kozy]

I could hear and feel vacuum on the line. Didn't feel any change in vacuum by selecting different modes either, but never thought to listen for relays clicking. I'll check that shortly.

How easy are either of these devices under the glove box to replace?

[kozy]

I can hear a faint clicking on only two of the five modes. Sounds like the vacuum-electric heater control module may be bad?

Komrad, you said that there should be 10 hoses connected to that module. With my head in the passenger footwell, I can only see 5 hoses and not 10.

[komrad36]

If it's just the vac-elec module, that's easy enough to replace. It's about $53 on Amazon here:
http://www.amazon.com/gp/product/B000C9CBG0

Good news, I found a photo of the front side of it:


It's been a while but I seem to recall one electrical connector as well as a separate vacuum IN line from a (purple?) hose. Those two rows by five columns of short white posts you see in the photo are the vacuum OUTs are where all the actuators connect. This may differ between cars but I don't think so. You can pull them off easily as there's a mounting clip that holds all 10. Remove screws, remove electrical connector, and wiggle the thing out of place. Reverse process for reinstall.

[kozy]

The module in my car looks completely different from that. Check it out....

[komrad36]

I think it's the exact same and my memory just fails me. See that brownish translucent thing with the lines coming off? That's the cover over the white pegs! I thought 10 lines came out, but maybe it was just 5, and I was confused by the fact that there are 10 pegs. Pull it off (it's not attached by anything other than friction) and you should see the white pegs underneath. I know there's not a lot of working space, but it can be replaced relatively easily!

[komrad36]

I would follow the purple hose and make sure it's getting vacuum from the triangular vacuum tank where the outside engine line comes into through the firewall. If it is, and there are no obvious holes or tears or pinches in the purple hose, it's probably time to try replacing the vac-elec module.

[kozy]

The level of vacuum coming out of the hole on the triangle thing where the purple hose connects seems to be pretty weak. I'll try finding one of those at a junkyard to swap in and see if that changes anything.

At at first glance, I didn't see any bolts connecting that triangle thing to the center console at all. How is it secured on there?

[komrad36]

It's weak coming out but strong coming in to the triangle thing? ("Vacuum tank"?)

It's not just a tank, there's actually a built-in one-way valve inside so the engine can pull vacuum on it but it can't go back the other way under boost or other low vac conditions. Clever. It's possible that that has failed, I suppose.

You can also consider a new one; they're $18:
http://www.amazon.com/gp/product/B0016IRGE8/

Because of the one-way valve, it's critical that you have the two hoses in the right order!

It's attached by, if I recall correctly, two small bolts. Unfortunately, you can only access one from the passenger side. The triangle is a long tank (see the amazon link) that stretches across toward the driver's side - that's where the other bolt is, so you'll have to remove the plastic piece under the steering wheel to access that bolt too.

[Red99GTP]

The module in my car looks completely different from that. Check it out....

It is actually the same part as http://www.amazon.com/gp/product/B000C9CBG0. The yellow rubber cover with the vacuum line connections just slides off. I had the exact same problem on my 99 GTP. The solder connections inside the control valve cracked. I saw at least 4 or 5 cracks with several more possible. Just take off the 2 bolts that hold it on and remove the valve. There are tabs on the valve that allow you to open up the box. Gently, pry them open. Just remelt all the solder joints on each solenoid.
I also had a vacuum line leak(from the engine) near my battery. So I spliced and replaced a small part of it.

[kozy]

Since my last post I have located MULTIPLE vacuum leaks under the hood. I've got them all fixed so far except for one major one, hopefully to be fixed tomorrow. I'll be curious to see if fixing these leaks is enough to correct the HVAC issues here.

[sugaryuk]

Mine was the same way when I got it. The line had a small break in it down by the battery.

I had same problem with mine, vacuum lines run close to the battery, mine got some battery corrosion on them and it ate a hole in one of the lines.

[kozy]

Got some time this weekend to tinker with this again. Pulled the vac-elec module and opened it up. All the solder connections were still good. Then, I had the genius thought about checking fuses. I pulled all the HVAC fuses and reinstalled them to reset the system. Noticed that the HVAC CTRL fuse location was empty and only had contacts in one of the two slots. I put a new fuse in there before I noticed this and never took the new fuse out.

Turned the car on and all of a sudden the vents change and work like they should. Don't know what I did, but YAHOO!

[Scottydoggs]

lol magic cars repairs, got to love it......