What's this switch used for? I don't think mind is working correctly.
When it is "in the cool" position....it just does touch the end of the pin that sticks out. When in the "heat" position, its no where close to touching it. Any help would be greatly appreciated.

Hump.

 

That isn't for water. I believe it's the thermostat switch.

 

that switch is on air conditioned cars and it shuts off the water thru a vacuum switch mounted on the firewall so the heater is not heating the cold air from the ac . there are typically several bad hoses and vacuum pods and a bad main vacuum can in those systems after all these years and they are a f'n pita to work on.

 

Barnett.....that is correct. Is it suppose to push in that pin or let it slide out? It goes to the valve under the hood. Which is one of the heater hoses. Mind only barely touches the switch. It does not move any part of it.( the switch) I think its suppose to kill the vacuum when its in the "heat" mode? But the lever on the dash only moves it the distances that are in the pics. Is the switch pin out as far as its suppose to be?

FF351....the A/C stat is just above this switch. I'll take a pic and post it up.

Thanks,
Hump

 

huh? Man was I off base. I need to dive back under there and see what I have going on because from what Barnett says, I've screwed the pooch on plumbing that up.



Thanks for the knowledge drop.

 

Here is a pic of the A/C stat. Also.....what kind of vacuum should I have at the water switch? I have 15".

 

ok, welcome to vacuum vent hell.

the pin looks like it is out all the way.

the arm the cable moves should pressit in almost as far as you can press it in with your finger . in other words, the arm should almost bottom it out.

there is an adjustment for the cable on the bracket if you need to move it to get the arm to close the valve . just loosen the tiny sheet metal bolt on the underside around 3/4 turn, then move the cable accordingly . there are some cases where some retard has bent the arm by hand . if you can not adjust it with the cable, you will need to bend it by hand.

these systems are fkd and usually need around 18 hg of vacuum to work so set your idle up a little to test it . if there is not 18 hg, the heater vent may open so the vent can open when you are at a stop but it will close as soon as you are going at a steady throttle on the highway . isn't that nice?

remove the plug from the switch on top and clean the terminals and make sure they fit tight.

the valve under the hood is often bad . connect it to direct intake vacuum on the carb port or something and see if the arm on top moves at least 45 degrees . it might be 90 degrees . i have tried very hard to forget . if it does not, it is bad . autozone and rock auto may still have them.
.

 

Thanks for the post-up Barnett. I'll have to try that intake vacuum procedure. Only the valve under the hood doesn't have any levers. I'll post up a pic of it. Kinda looks like A/C expansion valve but I know it's part of the head side. I do know that the damper right there at the 2 controls does work. Tried it the other day.

Hump

 

This is my heater water flow valve. Getting ready to go out and check the other ( The vacuum one) and see how easy it moves. I get the feeling that it may be a little hard to move? Going to pull it and check it out.




Thanks,
Hump

 

Wow, that is original and rotting away . You need to new water and vacuum hoses etc.

You need to remove that valve and clean the bejesus out of it then put vacuum to it to see if the valve inside actually closes.