What does the range relay look like? Is it near the starter solenoid?

 

I got the fan back, I didn't plug the resistor back in correctly. still no heat though

I put vacuum to each of the 3 small ports on top of the servo, but I didn't see anything inside move. Should I be seeing something moving that's attached to that small round thingy with the 3 ports on top?

 

Are you getting cold air? To get heat, the actuator in the power servo must be getting vacuum, making the arm retract and turning the blend door to HEAT.

It's also possible that the heater valve is not opening.

 

All hoses connected to the heater valve are hot, so I guess that is working. I put engine vacuum on the under hood servo and it moved the arm, but it still was blowing cold.

What does the smaller round piece on top with the 3 small vac lines do?

 

The round thing is a rotary vacuum valve. Depending on what the power servo wants (Heat or cold), it moves the doors in the dash. I believe it also opens/closes the heater valve.

I would clean the electric contacts and put a thin layer of dielectric grease over them.

 

Thx, what are those 3 vac ports for? Looks like they go to to the master switch, I'm assuming they control the fan speed? Also where are those electric contacts?

 

Those vacuum ports control the doors in the dash (and heater valve, I believe), so that the system does what the power servo dictates. Fan speed is controlled by the electric contacts in your photo, which route power through the resistors in the power servo.

Additionally, the Range Relay (passenger side wheelwell), gives two speeds to the entire range, controlled by the lever in your control panel (High or Low).

 

Master switch supplies 12V to the entire system. It does not control fan speed. Think of it as a vacuum actuated electric relay.

 

So if I put vacuum to any of those 3 ports I should see or hear something move?
What part is the electric contacts and also what does tgAt range relay look like? I don't see anything on the pass wheel well

 

Ok, took it out since the weather was ok. Fan was on high the whole time, even with the car still cold, but now it's coming out of the vents. Still no heat though. I put engine vacuum to the servo and the arm moved to the other side, and the fan shut off. Came back when I put the delay valve thingy back on the servo.
Don't know why I still can't get the heat to work though. The servo moves the door correctly on top of the cowl, and both heater hoses are hot on each side of the heater valve.

 

Out of curiosity, where are you located?

 

I'm in NJ

 

Anyone know what the spring with the screw attached on the blend door lever is for? It's on the piece on top of the firewall that the servo pulls back and forth. Is there a specific way to adjust the screw? I'm assuming that's what determines how much hot or cold air comes inside ?

 

That spring is there to allow some overtravel without straining the power servo or the blend door. Just make sure you get full travel in either direction.

 

Also, it allows you to adjust the door for the full closed/ full open postion. the screw lets you adjust the center position of the door and then the spring allows it to over-run as stated above.

 

Just curious, how can you tell if it's adjusted properly?

 

The plastic part attached to the blend door should not bottom out on the end of the slot in the power servo arm (fully open or fully closed).

 

The way I do it is putting a vacuum to the Power Servo, so that it goes into HOT mode. When the vacuum is released and the arm retracts, you want the overtravel spring to compress slightly, signifying that the blend door has reached its stop.

 

Can I do this by putting engine vacuum on the servo? Which spring is that over travel spring, is it the small one with the bolt attached or the large one on the other end?

 

Any vacuum source you want. You can even suck through a hose.

The second spring (I'm trying to remember what it looks like), I believe provides an overtravel protection on the other side of the stroke.

 

Hey, back again !

I've managed to manually move the lever on the firewall back and forth, changing from heat to cool, bypassing the auto part. Crude but it works and I don't have to do it that many times during the season

My issue now is that the air is only coming out of the vents, how can I get it to the floor when I'm using the heat?

 

What you are asking is done by the master servo. Rather than manually move the blend door, you are better off using the vacuum regulator I suggested and let the master servo do its thing.

It controls:
- Fan speed
- Where the air comes from
- Air temperature