|
|
|
Re: 71 B Body A/C Heater Valve ID
[Re: scatcity]
#2689863
08/20/19 09:29 PM
08/20/19 09:29 PM
|
Joined: Jan 2003
Posts: 2,016
Frederick, MD
71charger
top fuel
|
top fuel
Joined: Jan 2003
Posts: 2,016
Frederick, MD
|
I don't know if I can adequately describe how the vacuum control switch works, but I will try. There are seven vacuum nipples, one of which is connected to engine vacuum, the others to the various actuators. Behind those nipples is a sliding plastic block sealed with grease against the backside of the seven vacuum ports/nipples. As you move the selector, the lever slides the plastic block back and forth changing which port gets engine vacuum. On the side (top or bottom, I forget) of the sliding block are three ramps which ride across three electrical contacts. This changes which plugs on the five-way electrical connector are live. Off of the main vacuum harness, one of the hoses tees off and connects to the back of the heater controls to provide vacuum to the variable control from which the the other hose goes to the water valve.
The vacuum nipples get brittle with age and break off.
|
|
|
Re: 71 B Body A/C Heater Valve ID
[Re: 71charger]
#2689998
08/21/19 12:08 PM
08/21/19 12:08 PM
|
Joined: Apr 2003
Posts: 705
Morningside, Long Island
scatcity
OP
super stock
|
OP
super stock
Joined: Apr 2003
Posts: 705
Morningside, Long Island
|
I don't know if I can adequately describe how the vacuum control switch works, but I will try. There are seven vacuum nipples, one of which is connected to engine vacuum, the others to the various actuators. Behind those nipples is a sliding plastic block sealed with grease against the backside of the seven vacuum ports/nipples. As you move the selector, the lever slides the plastic block back and forth changing which port gets engine vacuum. On the side (top or bottom, I forget) of the sliding block are three ramps which ride across three electrical contacts. This changes which plugs on the five-way electrical connector are live. Off of the main vacuum harness, one of the hoses tees off and connects to the back of the heater controls to provide vacuum to the variable control from which the the other hose goes to the water valve.
The vacuum nipples get brittle with age and break off. Your explanation is perfect, thanks I have a few spares so diagnostics hopefully go well. Appreciate the input. 
|
|
|
Re: 71 B Body A/C Heater Valve ID
[Re: 71charger]
#2691122
08/25/19 08:03 AM
08/25/19 08:03 AM
|
Joined: Jan 2003
Posts: 3,704
MICHIGAN
DynoDave
master
|
master
Joined: Jan 2003
Posts: 3,704
MICHIGAN
|
Here are the guts of a '71 Charger heater/AC switch. This one was still working? Looks good inside....
|
|
|
Re: 71 B Body A/C Heater Valve ID
[Re: DynoDave]
#2691146
08/25/19 10:18 AM
08/25/19 10:18 AM
|
Joined: Jan 2003
Posts: 2,016
Frederick, MD
71charger
top fuel
|
top fuel
Joined: Jan 2003
Posts: 2,016
Frederick, MD
|
Here are the guts of a '71 Charger heater/AC switch. This one was still working? Looks good inside.... All the nipples were broken off, so I sacrificed it to take some photos of how it works.
|
|
|
|
|
|
|
