Author Topic: Help with HVAC?  (Read 2702 times)

Offline 75scottsdale

  • Newbie
  • Posts: 6
Help with HVAC?
« on: September 30, 2013, 01:47:20 am »
Hey guys, I got a 75 Scottsdale with factory a/c and I was needin a little help with the HVAC vacuum hoses under the dash.

Whoever owned the truck in the past decided to cut hoses and do all other sorts of crazy stuff under the dash lol.

Im just wantin to know if someone can post some pics or a diagram of the vacuum lines under the dash, Some pics of the heater and a/c boxes would be nice to if any of you guys wouldn't mind takin a few minutes to snap a few pics, just to have a visual of what things should look like.

Im a mechanic at a farm service shop so im familiar with HVAC and how things operate I just need something to go by, thanks guys.
« Last Edit: December 10, 2013, 01:52:11 pm by Captkaos »

Offline Jason S

  • Senior Member
  • ****
  • Posts: 1561
Re: Help with HVAC?
« Reply #1 on: September 30, 2013, 07:19:19 pm »
Schematics and diagrams are here: 

http://forum.73-87chevytrucks.com/smforum/index.php/topic,25639.0.html

The bulk of the information you'll need (i.e., vacuum schematics) should be in the '74 Light Truck Service manual with any additional changes in the '75 Supplement. 

As you may have already know, '73-'75  HVAC systems were different than the '76-up systems, including: the dash control panel, underdash portion of the system, electrical wiring and general operation. 
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"

Offline 75scottsdale

  • Newbie
  • Posts: 6
Re: Help with HVAC?
« Reply #2 on: October 02, 2013, 11:06:05 pm »
Alright, ill try and get one of the service manuals in.
Thanks for the link and info bud.