1972 Vega GT with a/c - fan blower stays on high setting

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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby Monza Harry » Sat Sep 27, 2014 1:15 am

They are available on eBay, and maybe elsewhere(?) Here are a couple: http://www.ebay.com/itm/NOS-71-72-73-74 ... a8&vxp=mtr and another one http://www.ebay.com/itm/NOS-1971-1975-C ... ad&vxp=mtr but there is also another switch back there on top of the position control not the hot/cold slide. Sorry I could not find a pic. Harry
Now I find that switch! :bang: Here it is.
[attachment=0]Monza Other A C Switch.jpg
Last edited by Monza Harry on Wed Oct 01, 2014 9:10 pm, edited 1 time in total.
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby corvairdog » Sat Sep 27, 2014 9:24 am

Ok, I'm really frustrated at this point. I just tried replacing the blower a/c switch with a NOS one and the fan still runs on high. It's hard to get the old switch out so I just unplugged it and tried the new switch and nothing changed.

It really looks like the fan is hard wired to high but I had someone look at it and he said no. How can I troubleshoot this? I'm thinking the fan must be hard wired on high and the blower switch is being bypassed.
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby stage169 » Sat Sep 27, 2014 12:52 pm

Take a look at these, it is for 1977 but they may help. Going off memory the Air Inlet Valve Switch will run the fan in High. 65 is high, 63 the lowest speed, etc... The small relay at the bottom is to delay the AC for a bit after starting the engine. Brian
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1977VegaACwiring.jpg
1977VegaACwiring.jpg (148.35 KiB) Viewed 272 times
1977VegaTSGblowermtr.jpg
1977VegaTSGblowermtr.jpg (72.88 KiB) Viewed 272 times
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby corvairdog » Wed Oct 01, 2014 11:10 am

Forum member DadHad1 lives local to me and helped troubleshoot and resolve this issue. After trying to replace both the blower resister and the fan switch Mike determined the issue to be the "air inlet valve switch" located under the right side of the dash. We unplugged it and now all 4 fan speeds work properly. Does anyone know if this can be left unplugged or what this part does? I took a picture of it.
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby stage169 » Wed Oct 01, 2014 6:22 pm

From my understanding if the upper lever (AC Max or Norm) is in the Max position the air inlet valve switch should be made so the fan runs on High regardless of the fan switch position. Depending if the operator for the air inlet valve switch is vacuum open or vacuum closed (I think it should be vacuum closed, switch made but I'm not sure) then you might have a vacuum issue or a stuck air inlet valve operator or stuck switch. Just what you wanted to hear.

For every position the air source is outside except when the AC is in Max. Hopefully it is simple but I would want the AIV open unless you are running the AC on a super hot day.
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby corvairdog » Sat Oct 04, 2014 11:18 am

I think I solved the issue. The vent was stuck partially open which was causing the air inlet valve to be stuck. Once I freed the stuck diaphragm lever assembly my fan works!

IMG_20141004_110400678.jpg
IMG_20141004_110400678.jpg (32.38 KiB) Viewed 243 times
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Re: 1972 Vega GT with a/c - fan blower stays on high setting

Postby Ckill » Sun Oct 05, 2014 10:58 am

Awesome good fix. Glad you found the problem. :th: :th:
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