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RESOURCE G Body HVAC Vacuum Line/Wiring Routing 2020-10-02

MrSony

Geezer
Nov 15, 2014
6,082
113
Des Moines, Iowa
MrSony submitted a new resource:

G Body HVAC Vacuum Line/Wiring Routing PART 1 - Vacuum lines and wiring harness routing for most G-Bodies.

Pics are ordered working your way from the engine compartment harness towards the HVAC controls in the dash.

I can get more pics if need be, but keep in mind my car at the time of posting only has the front clip off.

Pic#11: Grounds, ringlets go to passenger fender, black plastic plug is grounded to tab on blower motor.
View attachment 158470

Pic#10: Purple power wire to blower motor.
View attachment 158471

Pic#9: Orange, light blue, red, purple (faded), and...

Read more about this resource...
 

mikester

Royal Smart Person
Mar 10, 2010
1,971
113
Small town NY
One thing you might want to add is the vacuum actuators have two different size hose ends. A small thin metal one and a thick larger diameter plastic one. Maybe it was a change of design that occured in a certain year. My 83 Malibu wagon has the thin metal. The late 80s Olds Cutlass sedan that I pulled the vacuum lines out of had the larger plastic.
Also the 4 wire plug on my wagon has the red wire going to a splice with the red coming from the alternator. The dark green and black go to the compressor and the light green goes to the high idle circuit.
 
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MrSony

Geezer
Thread starter
Nov 15, 2014
6,082
113
Des Moines, Iowa
One thing you might want to add is the vacuum actuators have two different size hose ends. A small thin metal one and a thick larger diameter plastic one. Maybe it was a change of design that occured in a certain year. My 83 Malibu wagon has the thin metal. The late 80s Olds Cutlass sedan that I pulled the vacuum lines out of had the larger plastic.
Also the 4 wire plug on my wagon has the red wire going to a splice with the red coming from the alternator. The dark green and black go to the compressor and the light green goes to the high idle circuit.
My car has all the same size nipples on all actuators.
 

mikester

Royal Smart Person
Mar 10, 2010
1,971
113
Small town NY
My car has all the same size nipples on all actuators.

Mine does too but it seems like GM had two different style actuators. From what I can tell some are metal and some cars have plastic. The nipples on the plastic are much larger so the tube ends are too big to fit the metal ones.
Instead of trying to replace the actuators Im going to cut the tubes and use my ends on the replacement setup I got from the Olds at the junkyard. Crazy as it sounds I found some small clear fuel line at the local mower shop that has the ID of the vacuum line OD. I cut an inch of the fuel line, slipped the two pieces of vacuum line into each end and it was a nice tight fit. A drop of super glue on the outside and Im thinking its going to be an easy fix I'll post some pictures when I get it done. I'll also post a picture showing the difference in the two ends.
 
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Reactions: MrSony

MrSony

Geezer
Thread starter
Nov 15, 2014
6,082
113
Des Moines, Iowa
Mine does too but it seems like GM had two different style actuators. From what I can tell some are metal and some cars have plastic. The nipples on the plastic are much larger so the tube ends are too big to fit the metal ones.
Instead of trying to replace the actuators Im going to cut the tubes and use my ends on the replacement setup I got from the Olds at the junkyard. Crazy as it sounds I found some small clear fuel line at the local mower shop that has the ID of the vacuum line OD. I cut an inch of the fuel line, slipped the two pieces of vacuum line into each end and it was a nice tight fit. A drop of super glue on the outside and Im thinking its going to be an easy fix I'll post some pictures when I get it done. I'll also post a picture showing the difference in the two ends.
if it works it works.
 

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