Ok I hope someone has had the same problem I have now. I have a 71 electra Here's the story.... When to turn on the fan, I get nothing until I put it on Defrost/De-ice setting then it works Low Med and High ie normal. Also it works on "AC" and it only comes on when you put it on max IE recycle and the fan blows only high, even if you play with the switch low to high etc. If I remember correct the Max AC setting was allways on high fan, so this may not be part of the problem. So I get 0 fan on all settings except max ac and De-ice. So on normal temp control only De-ice works and on recycle only ac works but on high all the time. Confused? Me to! Could this be the blower relay? A vac problem? I looked at the vac lines under the dash they look good. I just put on a new A6 ac comp today and switched to 134 its cold but I only have max ac so it gets REAL cold after a few min and I can't turn it down! So its on and off and on and off and window down and window up.
Many vacuum lines at the dash controls. My bet is you have some leaks. If you get to the point where you are able to check the hoses & routings do not follow the chassis manual. I have a dealer bulletin I can send you for '71 stating the drawings are wrong. Correct drawings are included.
Ran down the vac as best as I could, looks fine. Could a bad blower relay cause this problem? I might just order one from the Auto parts place $20 and it would be here Fri. What could it hurt to try?
The electrics on that car are much more complicated than a Skylark/GS. You'll need to get a Chassis Manual to sort out procedures & sequences on how the system works before trying to change parts. I have a '71 edition, Section D is Auto Climate Control for 45-46-48 & 49000 series cars, 78 pages. The relay sounds like it's working. The fan runs in certain positions. Control is your issue.
Yea I think you are right. Drove it all day today 91 outside but my AC was working super fine. On high only! I will have to get back on it this week.
