1996 pontiac bonneville duct foor

Thank you.

By "vents" I assume you mean the dash vents typically used for AC.

If flow normal when set to defrost and fan speed on highest?
Does the air out the "floor" setting give a good volume?
If so, I'd suspect, when in AC dash mode, some of the air is coming out the defrost along with the dash. 2nd would be that too much comes out the floor during AC because of the vacuum motor there not fully blocking off the flow.

Check the diaphragm with the blue tube going to it. Take off the driver's side hush panel under the dash to see the diaphragm that the blue tube goes to. With the blower motor running and control setting on AC, see if you can reach your finger behind the diaphgram and push the diaphragm toward the back of the can That's the way it should be sucked by the vacuum when "on."

If you can move it further, see if the dash vents are now giving better flow?

You can check to see if you're getting good vacuum to the programmer control box from outside by taking the violet hose off the black hose that comes in through the firewall on the passenger side. Let the running motor suck on your finger tip and see how strong it feels compared to the vacuum getting the blue tube at the diaphragm when the AC is called for.

You can do the bypass with aquarium tubing or 1/8 in internal diameter gasoline hose from auto parts store. Need about 1 - 1.5 inches length for each one.
http://www.imcool.com/articles/aircondition/fix_vacuum_line.php

Another test I did was take a hose off one of the other motors and apply it to the blue diaphragm and change the AC until it actuated and see if the diaphragm sucks in fully with a different hose. That would tell you your vacuum from the motor is okay and you don't have a rotted hose or cracked reservoir for the vacuum under the front fender.

Good luck.

« Previous
1
2
Next »
Last

To POST a message, please Sign In.

Forum Tools

Search Forums

Enter Keyword(s):

Browse by Category

Browse by Vehicle

Browse by Board

Browse by Topic

View All Topics

Learn More, Do More

Edmunds Community

Explore Edmunds