When I speed up the air conditioner switches over to the defrost from vent. And then back to the vent when the RPMs go down. Same on heat or A/C.
Aug 12, 2009 at 4:33 PM
1994 Ford Taurus A/C AND HEAT
1994 FORD TAURUS
DARRYLPQ
- MEMBER
- 1 POST
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JGAROFALO
- ✓ASE Certified Mechanic
- 489 POSTS
[quote:f4d4c99f51="DarrylPq"]Air Conditioning problem
1994 Ford Taurus 6 cyl Front Wheel Drive Automatic 87000 miles
When I speed up the air conditioner switches over to the defrost from vent. And then back to the vent when the RPMs go down. Same on heat or A/C.[/quote:f4d4c99f51]
You have a vacuum leak. When you accelerate or are pulling under load (like going up a hill), your vacuum drops. There is a reservoir and check valve in the system to maintain the vacuum under these conditions. The problem could be one of the following:
Bad check valve (not holding the vacuum)
Leaky reservoir (vacuum leaking out)
Bad vacuum motor on the heat/defrost door.
All of these are readily accessible and easily replaced. You need to figure out which one is causing the problem.
To do this, start with the engine running, and listen for a hissing sound under the dash or under the hood.
1994 Ford Taurus 6 cyl Front Wheel Drive Automatic 87000 miles
When I speed up the air conditioner switches over to the defrost from vent. And then back to the vent when the RPMs go down. Same on heat or A/C.[/quote:f4d4c99f51]
You have a vacuum leak. When you accelerate or are pulling under load (like going up a hill), your vacuum drops. There is a reservoir and check valve in the system to maintain the vacuum under these conditions. The problem could be one of the following:
Bad check valve (not holding the vacuum)
Leaky reservoir (vacuum leaking out)
Bad vacuum motor on the heat/defrost door.
All of these are readily accessible and easily replaced. You need to figure out which one is causing the problem.
To do this, start with the engine running, and listen for a hissing sound under the dash or under the hood.
Aug 15, 2009 at 6:46 AM
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