BStone

Well thought I was getting sorted. Re-installed the heater control with the vac tubes well coneected and the defrost and heaters brouting air correctly.

My switch is only operating on high or off but I blame that on one of the heater resistor coils being broken pending replacement.

I noticed however that now the air will not blow hot. It did before when the defroster was not cycling correct but now, there is no actual heat coming througheither the deforst or the heater.

As part of my overhaul, I have replaced the blower motor and routed the vac system at the engine as per the diagrams.

The one thing I did notice was that there does not seem to be any vacuum at the water valve. Is this normal?



Any ideas where to start next on this?

oldcutlass

I think you answered your own question here! Trace you water valve vacuum back to the source and see why you have no vacuum there. Once you have that fixed you will also have heat!

rocketraider

On an A/C car you should have vacuum at the water valve in all positions except MAX A/C. My guess is you either have a vacuum hose on the wrong port of the control (not hard to do) or the selector valve itself has failed.

This isn't a Comfortron car is it? If it is, that opens up a whole new can of worms.

Lady72nRob71

First of all, we need to know what year and model.
There are two types of water valves used throughout the years. One used vacuum to open, one uses vacuum to close. In 72 vacuum closed it, so water would flow with no vacuum. Your year could be the reverse. With engine running at normal temp, and heater on hot, feel both heater hoses - they should be pretty warm to hot. If not, use a small clean hose and connect to water valve. Suck on the hose and see if the hoses heat up. If it does, then loss of vaccum is the cuase and you have a normally closed valve.

jaunty75

He's got a '67 Delta 88.


One thought that comes to my mind, and it's probably a dumb question, but you do have the engine running and warmed up, correct? Can't get heat from a cold engine.

BStone

Well think I got this one figured. There is a 2 port vac switch on the back of the control unit. The one line runs to the water valve and the other is vac. The switch had clogged with corruption so used a small bit to clean the crud and blew it out. The switch is to cut off heating and permit cooler air when a/c and cool is selected if I understand correct.

The PO had rerouted the engline vac lines to run the water valve thus allowing it to actuate and permit hot air. When I put the vac lines correct, the weter valve closed due to no vac and thus - no heat!

Now I just need to verify the 4 position switch is good and replace or repair the heater resistor. The fan blows on high only. The resistor itself has one busted coil so not sure if this would prevent any intermediate fan speeds.

The only other issue is the switch which I took out and can see it is busted up and fried. No doubt this is why the PO bypassed it.

Thanks for the assistance and letting me vent/work through this merry process!

Colin

BStone

OK so one step closer tonight. Took the 4 way switch apart and cleaned it and re-assembled. Swapped the brown hot lead and the black/orange lead in the T connector and now have all speeds less low. If I flick to low it grounds out and blows the fuse.

Not sure if this is due to a bad ground or bad switch still

BStone

Bad speed switch was grounding out. Less the main power switch which is bypassed, the heater now actually blows on all 4 speeds and diverts to heater/defroster.

That was painful!

jaunty75

But isn't there some satisfaction in finally fixing it! I bet that's the first time that ventilation system has worked properly in many years.

BStone

Mostly fear that it will simply fail again!

oldcutlass

Wtg!!!!

BStone

Alright so replaced the heater blower swotch with a NOS one and replaced the dvr side air hose with some small size dryer vent . Actually managed to mash it all in there and all seems to be working now.

It all squeezes in their pretty tight!