well, i look at the plastic box and couldnt tell if the hoses where cracked/woren out. My air flow if tricky at times. sometimes the air will blow fine out of the middle vents and then sometimes when i brake or when i hit a small bump the air flow will swich to the defrost windshield. it works normal about 50% of the time

Your brake booster is vacuum actuated. It does sound like a vac problem.

ok, Im still stuck i think its something else. I check the cainster and on a 95 bonneville it has 2 hoses connect to the bottom of the plastic box. I unplugged, checked, connect and rechecked and it seems to work fine for about a day then it start the same problem. :?:

To check for the canister holding vacuum what I did was run the motor. Turn it off then pull off the out line and you should get a good whoosh as the air goes in it as the vacuum holds for several seconds.

You may have a line that'* cracked and opens when you hit a bump that jiggles it. You need to carefully examine all the line from the intake manifold to the interior of the car. That means getting under the dash, take off the hush panel, look for the violet 1/8 inch vacuum line that goes up above the glovebox and connects at a fitting to a black line coming through the firewall. You should be able to pull that line off and get full vacuum sucking on you fingertip when the car is running and for 15 seconds at last after it'* shut off as the vacuum canister leaks down.

Do all other checks first. That last one is a bear to do unless you young, short, thin, and have slim fingers that don't get cut!

Then you can start learning which of the output vacuum lines from the programmer should have vacuum in which modes based on their color. And you test each of them to see if you get vacuum to them when the programmer is switched-with motor running.

If you have vacuum to the interior programmer box even when it doesn't switch to the right modes, someone can look up the colors in the output lines from a factory service manual.

Here is the vacuum diagram for automatic climate control from a "95 FSM. (Presuming I have the correct page ) It shows the vacuum source at the engine (intake manifold) and all the other HVAC vacuum connections for your car. Colors will hopefully be correct as well. Notice there are two single acting and one double acting vacuum actuator and lots of places for vacuum to leak.

BTW.. if you vacuum test with a gauge...there should be no leakdown on a good system.

I dont no if this might be a culprit of the vac problem but about month a go i replaced the blower motor and in installing the motor i cracked off a nice size piece of plastic on the firewall right below the blower motor. The cracked off piece of black plastic exposed a yellowish looking insulation or filter. I can get pictures if needed??

That is typical when replacing a blower motor and it shouldn't have any bearing on the stalling. Cracked t fittings or vacuum tubing would though.

Guys, Im still stuck on this. I check the line from the cainster to the firewall everything looks good, next i took the plastic panel under the glovebox off and found some sort of tube holder close to the floor of my car it had about 6 colored tubes all connect to it. I found the violet tube but couldnt locate where it came from. I think its time to take the HVAC out?? and manually check the tubes????

Do the tubes look like this?


Check out this thread..it is a long read (because some idiot BC member hasn't cleaned it up yet, like I...I mean, HE promised he would ), but it references alot of what has been said and other info you need.

I have another write-up somewhere here on replacing the HVAC connector where the colored lines go into. Don't need to pull the programmer completely, just undo the bolts on the case enough to get the balck connector out. The nipples inside the connector collapse and caus ethe air to go into default mode (Floor and defrost).
http://www.bonnevilleclub.com/forum/...r+centre+vents