seymouj
NAXLA Member #1223
- Location
- Shingle Springs, CA
When my engine is working hard (I mostly notice it when going up a hill on the highway) my ac or heat or whatever I have on switches to defrost on its own and then when I finish climbing the hill and let off the gas, the air switches back to the vents.
If I understand correctly, that switch is vacuum controlled and is in the defrost position when there is no vacuum. It would seem I don't have enough vacuum to operate the switch when climbing a hill.
I looked for vacuum leaks including near the canister under the front bumper and near the battery (because I read somwhere that is a common place for leaks) but didn't find any.
I can live with the loss of AC or heat blowing on me for a couple minutes but I am concerned that the low vacuum might be a symptom of a bigger problem.
Any suggestions on what I should check or if this condition suggests a bigger problem?
87, 4.0, auto, 190,000 miles
If I understand correctly, that switch is vacuum controlled and is in the defrost position when there is no vacuum. It would seem I don't have enough vacuum to operate the switch when climbing a hill.
I looked for vacuum leaks including near the canister under the front bumper and near the battery (because I read somwhere that is a common place for leaks) but didn't find any.
I can live with the loss of AC or heat blowing on me for a couple minutes but I am concerned that the low vacuum might be a symptom of a bigger problem.
Any suggestions on what I should check or if this condition suggests a bigger problem?
87, 4.0, auto, 190,000 miles