'91 Heater A/C control
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'91 Heater A/C control
My A/C suddenly started switching from panel vents to floor and to windshield and then back with braking and acceleration. The '91 was a transition model re: the dash control (per Chilton) but not trusting them as to manual, vacuum or both,(not clear), I don't want to start ripping that apart if it is in fact vacuum control. Perhaps a vacuum leak?
Anybody run into this problem, or can tell me where to start to check for vacuum and how much I should expect??
Anybody run into this problem, or can tell me where to start to check for vacuum and how much I should expect??
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From: Easton,Ks
You are right it is a vacuum leak. You might start looking at the vacuum hose to the vacuum motor under the hood by the heater. Also look under the hood and check the vacuum hoses that go to the round plastic ball, there will be a "T" in this hose that feeds the vacuum to the dash. This is about all you can check without taking the dash apart.
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From: Easton,Ks
Originally Posted by '91 Silver Devil
Thanks Subford
BTW, I'm new here, nice to find a Board for F Series Trucks.
Any idea what I should see for vacuum levels off that "T"???
Anyone?
BTW, I'm new here, nice to find a Board for F Series Trucks.
Any idea what I should see for vacuum levels off that "T"???
Anyone?
Here is a 1995 Diagram, yours should be the same other than the colors of the hoses.
The Vacuum Tank in the Diagram is the Black Ball and vacuum level should hold real close to your max engine vacuum unless you move a **** or have a leak even when you go to WOT and the engine vacuum drops the vacuum at the Ball should hold.
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Thanks Subford,
My control panel is quite different, but that does give me the idea. I think I'll try to find a diagram like that for my '91, and go from there. That was from WWWfordtrucks.com ? Research time.
Thanks again.
My control panel is quite different, but that does give me the idea. I think I'll try to find a diagram like that for my '91, and go from there. That was from WWWfordtrucks.com ? Research time.
Thanks again.
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From: Easton,Ks
Originally Posted by '91 Silver Devil
Thanks Subford,
My control panel is quite different, but that does give me the idea. I think I'll try to find a diagram like that for my '91, and go from there. That was from WWWfordtrucks.com ? Research time.
Thanks again.
My control panel is quite different, but that does give me the idea. I think I'll try to find a diagram like that for my '91, and go from there. That was from WWWfordtrucks.com ? Research time.
Thanks again.
That is why I posted it for you. The dash may look different with different controls but it is still the same vacuum diagram.
Last edited by subford; Jun 10, 2006 at 01:12 PM.
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Thanks to you Subford, you nailed it! Had I searched the archives, where that exact problem is spelled out, right down to the location of the leak in the"white vacuum line", I would have saved you the trouble. It's working fine now, thanks.
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