what's wrong w/my a/c and heat ??
12-22-2003, 05:37 PM
#1
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Join Date: Dec 2003
Location: Waco, TX
Posts: 2,076
what's wrong w/my a/c and heat ??
I was wondering if anyone else has had this problem before. I have a 95 Formula and have had a 93 Z28 and both cars had the same thing wrong w/them. When I'm in 5th or 6th gear (dosent matter) and I have my a/c or heater on and I start to go up an incline or hill the air cuts out and dosent blow out my vents for that time. Then when I get back on straight road it starts blowing out my vents again w/no problem..anyone know what the prob is ?
12-22-2003, 07:23 PM
#2
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Join Date: Feb 2003
Posts: 270
Well you have the proverbial vacuum leak that we all have to our HVAC controls. Took me 3 weeks to find mine. A little history is in order.
The HVAC controls default to defrost/floor. When all the vacuum is gone, the HVAC will blow defrost and floor, no matter what the temperature is set for. When you loose the vacuum to hold the HVAC doors to another setting, the system defaults or falls to defrost/floor. Check it out the next time you are driving and floor the throttle. You don't have to go up a hill to see it happen. When the vents cut off you can feel it at the defrost and floor position.
This may help
http://shbox.com/1/vac_check_valve.jpg
This is the vacuum check valve at the passenger engine side fire wall. If you have vacuum there the problem is most likely in the cockpit.
Check all the positions of the HVAC system. Mine turned out to be the hose came off the bi-level actuator. Everything work but the bi-level setting. When I was in any other setting, and I got on the throttle, the blower appeared to slow down until the engine speed settled down.
Good luck to you
The HVAC controls default to defrost/floor. When all the vacuum is gone, the HVAC will blow defrost and floor, no matter what the temperature is set for. When you loose the vacuum to hold the HVAC doors to another setting, the system defaults or falls to defrost/floor. Check it out the next time you are driving and floor the throttle. You don't have to go up a hill to see it happen. When the vents cut off you can feel it at the defrost and floor position.
This may help
http://shbox.com/1/vac_check_valve.jpg
This is the vacuum check valve at the passenger engine side fire wall. If you have vacuum there the problem is most likely in the cockpit.
Check all the positions of the HVAC system. Mine turned out to be the hose came off the bi-level actuator. Everything work but the bi-level setting. When I was in any other setting, and I got on the throttle, the blower appeared to slow down until the engine speed settled down.
Good luck to you
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