AC switch went....... I am assuming...

[Headshot zod]

Ok I did a search here and there seems to be a design flaw with the switch.



I know the ac unit works... .....



I am pretty sure the blower works... .....



I have been using it on high for the past few weeks.



The vacuum actuated stuff still seems to work as I can switch it to heat the I get heat blown in even though its not fan driven.



What is the best way to troubleshoot the system to see where the problem is?

 

[JMariotti]

LOL I have an interesting problem with mine too. It works great on high and blows ice cold. However when you try to use the low setting it blows heat... . go figure

 

[tugboatphil]

HZ,



You didn't really make your problem clear to me. But on my 90, it stopped blowing cold. I had just had it in the shop for something (can't remember what) and I didn't make the connection. Spent a couple of weeks searching through the system, with no luck. Finally took it to a different shop. Out on the firewall was a t-fitting for the vacuum switch. One line had gotten pulled loose and apparently some genius plugged it with a toothpick. I hadn't even looked out there, as I didn't realize it was part of it.

 

[Headshot zod]

yes, I was contemplating that after the first response (doh!)..... to the point I couldn't believe I had actually posted something so vague



"That all depends on what the definition of "IS"... is" -bill clinton



And since I had just finished reading one of the few postings about the issue. I was still thinking heavily about it. So let me be a little more clear.



Everything (heat/ac/def/vent) was working fine, at all speeds.



I was driving the truck with everything on high, parked it. Came back a 1/2 hour later and "nothing"... .



Now the blower is not functional, at any speed, under any condition, at any time.



The actuator when I slide it from max ac to heat allows heat to enter the vehicle through whatever draft is coming through. But I think this is vacuum actuated.



Currently, when the vehicle is running and I hit the "max ac". The compressor does not engage.



It sounds like a blown fuse. But I checked them. Well... then it sounds like a loose wire or something in the switch.



Since I haven't had a chance to get a manual for the truck yet, I don't know how the AC is wired. When the AC is engaged, is the blower and the compressor on the same circuit. So I am not sure where to begin with this.



JMariotti..... I would suggest making peace with Mother Nature. It would appear as though both of her sons (h-miser and s-miser) are battling it out for supremacy deep within the innards of your temperature controls... ... pump up the volume!!!!!!

 

[Headshot zod]

Got real lucky..... the guy that owned the truck before did some cheesey wiring. AC works fine... Now I need to track down the "why isn't my alternator charging problem?" which has just manifested itself