Cruisinfanatic

Is it supposed to do that?

rodj

Have you got any vac to the HVAC controllers.
By default you get defrost if no vac

Pttrader

You didn't say what year your ride is. My 96 had the same problem and I finally ended up getting a NOS AC Programmer and that solved the problem. It is located under the left side of the dash right above the gas pedal. Just search the forum, there's some good info here.

70vert

If it's a 96 do an "ac controller" search or PM me.

Cruisinfanatic

It's an 85.
I seem to get equal amounts of air through the defroster, front vents, and the floor.
Just wondering if this is right. Had the car since new and the air has never worked all that great.
The heater, air controller levers seems to work fine, switching between modes
Where is that valve? Picture would be great.

harley 1951

I had same problem. Tech filled system with smoke and found ruptured vac line. Works great now. Vac line cheap. Tech not. My cruise also had cracked, collapsed, line. It now works perfect too. Before it was eratic.

89 Bob L

It sounds like a vacum hose. Check them first. If, that does not help, then check the programmer, under the drivers side dash near the brake pedal. Usually the programmer does not go bad, but some connections inside of it does. If you open it up you will see two capacitors in the upper right hand side. Over time, they heat up (you may see some brownish color on the board) which causes the contact to go bad. Simply resoilder the connections.

Cruisinfanatic

Looks like I probably found the problem.
Had the radio out to check vacuum lines and the red and pink ones coming out of the controller (what the hell is that?) were a snack for a mouse.
These are really tiny lines. How do you connect the ends? Shrink tube maybe?

aquablue96

MIne is a 96 and it blows out the defroster for 30 to 60 seconds when the car is first started but then blows properly. Just always assumed it was designed that way for some reason?

rodj

so long as you butt the lines up so the shrink won't collapse with the vac
Or a thicker tube sleeved over the outside and glued on

Cruisinfanatic

Got it all apart today and fixed 4 different lines with the shrink tubing. Works like a million dollars now. Thanks for the advice!!!

Wathen1955

My 96 does the same.

Cruisinfanatic

When there is no vacuum (car off), the defroster door is open

Andrew

The reason it is doing this is because the rubber nipples are collapsing. It should not take that long. If you remove the programmer and trim the nipples back about 1/8 - 1/4 of an inch, the delay is fixed. Mine switches immediately.

JerryMiranda

Like you, I thought this was normal, except this W/E it took a bit longer than usual for my 96 to work normal in A/C mode. It looks like I have one of those connector or unit problems too. This forum is great. I was just signing on to renew my supporting membership (if you can spare the $25, do it) and noticed the thread . Very timely for me and very helpful. Thanks guys. I might have to pick one of your brains a little further, depending on what I find when I crawl under the dash.

Andrew

No need for a new one. 99% of these problems are fixed by trimming the nipple back. Here are some pictures posted by Digital Disaster a while back that I used (scroll down to post 13). It is free, but you have to be a contortionist to get to the thing!!

http://forums.corvetteforum.com/c4-t...l-problem.html