AC controls not working, found it
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
AC controls not working, found it
My 2nd Vette, 1st C3. Air would come out where ever it wanted (dash, defrost or floor) regardless of control setting. Found that the headlights and AC shared same vac port off engine. Headlight system has a leak somewhere. With not enough vac on AC side controls behaved badly. Plugged the headlight line at the vacuum tank giving full vac to AC controls and they work.
now if I can get that blasted vacuum tank out and repair it
now if I can get that blasted vacuum tank out and repair it
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
My 2nd Vette, 1st C3. Air would come out where ever it wanted (dash, defrost or floor) regardless of control setting. Found that the headlights and AC shared same vac port off engine. Headlight system has a leak somewhere. With not enough vac on AC side controls behaved badly. Plugged the headlight line at the vacuum tank giving full vac to AC controls and they work.
now if I can get that blasted vacuum tank out and repair it
now if I can get that blasted vacuum tank out and repair it
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
You don't have to keep the tank....unless you want it to work right. Ever try to start from a dead stop in the rain with the wipers on...without the tank. They quit working until you back off the accelerator. 
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
My 2nd Vette, 1st C3. Air would come out where ever it wanted (dash, defrost or floor) regardless of control setting. Found that the headlights and AC shared same vac port off engine. Headlight system has a leak somewhere. With not enough vac on AC side controls behaved badly. Plugged the headlight line at the vacuum tank giving full vac to AC controls and they work.
now if I can get that blasted vacuum tank out and repair it
now if I can get that blasted vacuum tank out and repair it
Burning Brakes
Joined: Oct 2001
Posts: 911
Likes: 5
From: TN
vacuum wipers
my 68 and 70 came from the factory with electric wipers, once the wiper door is open the wipers work whenever the wiper switch is in the on position. Stoping and driving off has not ever affected the wipers from not working, in fact they will wipe without the motor running.
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
I pulled the line taking vacuum to the tank bypassing it and the rest of the light assmbly. The Hoses feel and look good. One servo is new, the other a little worn looking. Can't get my fat head far enough in to see the control valves. Will try to borrow mirror from wife later tonight.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I pulled the line taking vacuum to the tank bypassing it and the rest of the light assmbly. The Hoses feel and look good. One servo is new, the other a little worn looking. Can't get my fat head far enough in to see the control valves. Will try to borrow mirror from wife later tonight.
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Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Good luck with the car.
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
T
I put a T in at lunch. The lights go up and down sort of. The one goes up, then the other. Turn them off and the one goes down then the other. The 2nd light does not move until the first has finished moving and the first to move switches depending on up or down.
I love old cars!
I love old cars!
Intermediate
Joined: Jul 2008
Posts: 41
Likes: 0
From: Raleigh NC
I put a T in at lunch. The lights go up and down sort of. The one goes up, then the other. Turn them off and the one goes down then the other. The 2nd light does not move until the first has finished moving and the first to move switches depending on up or down.
I love old cars!
I love old cars!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I put a T in at lunch. The lights go up and down sort of. The one goes up, then the other. Turn them off and the one goes down then the other. The 2nd light does not move until the first has finished moving and the first to move switches depending on up or down.
I love old cars!
I love old cars!
Question is when the lights were not being used how did the AC controls work?
Melting Slicks
Joined: Sep 2007
Posts: 2,429
Likes: 0
From: Tucson AZ
If the lights are operating independently, probable cause is a leak in a headlight vacuum hose. Mine did that until I replaced all the hoses, now, both are up and down together. And they're quick too. Worth the time and money.
