Heater/defrost control question

[Magic1]

Sorry for the new post but didn't want to hijack someone else's. When I bought my 82 Sierra k10 the only thing hooked up for the heater was the cable the attaches to the temp control switch. There were no electrical connections of any sort and someone had cut the vacuum lines under the dash. The plug was still attached but the lines only go under the dash a few feet and stop. I've rewired the truck and now have everything hooked up correctly minus the vacuum part. Since I'm not sure how it connects and what is actually missing can anybody give me a good direction to go. This is one of the few things left I've got to fix and am kinda stumped. Lol. If I could at least get defrost working I'd be in business but would like for it all to function rite.

[hoyle83]

I'm in a similar boat just haven't got the get up and go to tackle this yet...hopefully this thread will give me a boost!

[Magic1]

I ain't ever understood what would make someone just start cutting and gutting something instead of trying to fix it right. One thing that buying this truck has tought me is what to look for if I ever buy another like it. I've never seen so much stupidity crammed between two doors and under a hood as I have on this one. Whoever owned it before me shoulda left their tools put up and stuck with something a little easier. Like paper machete or stamp collecting. Lol 

[cvbear]

Isn't that the truth!  I have learned a lot about what to look for on my next project while working on our truck.  I need to do a top 10 post.  Amazing some of the stuff the prior owner(s) did.

[Jason S]

For the vacuum issues, have you looked through the factory service manuals?  There will be a breakdown of the vacuum hose color and where it belongs as well as the wiring.  Short of that, it may be easier to find a early 80's Chevy/GMC truck, Blazer/Suburban and remove the HVAC vacuum harness.

Service Manuals:
http://forum.73-87chevytrucks.com/smforum/index.php/topic,25639

[Magic1]

For the vacuum issues, have you looked through the factory service manuals?  There will be a breakdown of the vacuum hose color and where it belongs as well as the wiring.  Short of that, it may be easier to find a early 80's Chevy/GMC truck, Blazer/Suburban and remove the HVAC vacuum harness.

Service Manuals:
http://forum.73-87chevytrucks.com/smforum/index.php/topic,25639

No I haven't but I will. Thanks. So I guess I'd have to find a setup off a square body, a nineties model wouldn't work?

[Jason S]

Yes, if you are going to swap factory parts it will need to be from a square body. 

Off the top of my head, '73-'75 HVAC systems interchange between those years.  Then '76-'85 (somewhere in the mid 80's) interchange. Then there was another change around '86 which may have run through '91 on crew cabs, suburbans and blazers, I am unsure of later the years. 

There should be others that will post to correct or add details. 

Just as a side note if you find a complete HVAC system in a wrecking yard truck truck it can be completely pulled (i.e., ALL the parts) within a few hours.  If you are uncertain, thoroughly  study the manual or bring some printed pages to show what and where all the parts go.

[Magic1]

Yes, if you are going to swap factory parts it will need to be from a square body. 

Off the top of my head, '73-'75 HVAC systems interchange between those years.  Then '76-'85 (somewhere in the mid 80's) interchange. Then there was another change around '86 which may have run through '91 on crew cabs, suburbans and blazers, I am unsure of later the years. 

There should be others that will post to correct or add details. 

Just as a side note if you find a complete HVAC system in a wrecking yard truck truck it can be completely pulled (i.e., ALL the parts) within a few hours.  If you are uncertain, thoroughly  study the manual or bring some printed pages to show what and where all the parts go.

I sure appreciate it buddy. I actually have a printed diagram of the vacuum layout but trying to compare it with real world parts that I haven't seen is a little confusing. I don't think mine even has the vacuum tank under hood. Why someone would just pull that stuff off beats me.

[Jason S]

I don't think mine even has the vacuum tank under hood. Why someone would just pull that stuff off beats me.

I'm glad I could be of help.  There are a number of people on here, myself included, that have found themselves in a similar quandary...

Keep us posted on your progress. 

[Magic1]

May take a little while but will do.