What are these parts pretty please?

[71CHEVYSHORTBED402]

71 Chevy with A/C:


No longer useful, good info. follows:

[John Pasinski]

Don't know what the 1st photo is, the 2nd looks like a relay plug. Headlight, horn, or A/C?

[haysonj]

The top one is the vacuum control for the heater hose under the hood and the passenger side vent door see attached diagram. I'm pretty sure the bottom one plugs into the back side of the fan switch

[71CHEVYSHORTBED402]

Originally Posted by John Pasinski

Don't know what the 1st photo is, the 2nd looks like a relay plug. Headlight, horn, or A/C?

Must be A/C. Don't know where it goes yet.

[71CHEVYSHORTBED402]

Originally Posted by haysonj

The top one is the vacuum control for the heater hose under the hood and the passenger side vent door see attached diagram. I'm pretty sure the bottom one plugs into the back side of the fan switch

Funny, I located the "Recirculated Air Door Diaphragm" name from that image. Probably your post. Do you mean plugs into the Control Head Vacuum Switch? Maybe that's the part in image 1? Switch throws me off, there's not an electrical connection. I guess "switch" doesn't have to involve electrical. Yeah, I'm pretty green.

[haysonj]

Originally Posted by 71CHEVYSHORTBED402

Funny, I located the "Recirculated Air Door Diaphragm" name from that image. Probably your post. Do you mean plugs into the Control Head Vacuum Switch? Maybe that's the part in image 1? Switch throws me off, there's not an electrical connection. I guess "switch" doesn't have to involve electrical. Yeah, I'm pretty green.

There is a electrical connection on the back side of the AC controls on the side toward the steering col. I thought it was right behind the fan control switch

[71CHEVYSHORTBED402]

The more I study that image the more it makes sense:

Port #1 on the Control Head Vacuum Switch connects to the Water Valve.

Port #2 on the Control Head Vacuum Switch connects to the Outside Air Door Diaphragm and the Recirculated Air Door Diaphragm. Therefore, the line that's loose is supposed to be hooked up to the Outside Air Door Diaphragm.

Port #3 on the Control Head Vacuum Switch connects to Vacuum Reservoir. This is the other one that's loose.

Ha!..........My Water Valve is connected to the Outside Air Door Diaphragm and nothing is connected to the Vacuum Reservoir. I'm no mechanic, but I think that means it aint doing *&%*.

Thank you for this information.

[71CHEVYSHORTBED402]

Originally Posted by haysonj

There is a electrical connection on the back side of the AC controls on the side toward the steering col. I thought it was right behind the fan control switch

The fan switch (Control Switch) harness was plugged in. The harness that's loose is something else.

I misunderstood your original post. Thought you were still talking vacuum lines.

[haysonj]

Originally Posted by 71CHEVYSHORTBED402

The fan switch (Control Switch) harness was plugged in. The harness that's loose is something else.

I misunderstood your original post. Thought you were still talking vacuum lines.

In the electrical section there is a color wiring diagram that you might be able to track down that plug by the color of the wires in it

[LockDoc]

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Here are a couple of pictures that show the vacuum switch location on the heater control.. I borrowed them from member "Classic Bowties" post.

LockDoc

[71CHEVYSHORTBED402]

Originally Posted by haysonj

In the electrical section there is a color wiring diagram that you might be able to track down that plug by the color of the wires in it

Sounds good. I'll check it. Thank you

[71CHEVYSHORTBED402]

Thank you Lock. I knew where it installed, just didn't know what it was. I have a better idea now. These trucks are cool. Learning a lot. At some point I'll need to determine how the vacuum lines are supposed to rout through the firewall. Things are a lot more difficult for the novice when they aren't factory correct.

Found just one of three cables was connected to the unit with a nut of some type. Doesn't appear any of them need it, but I'll probably add push retainer nuts anyway. I was pleasantly surprised how easy it was to remove, take apart, clean and reassemble. That said, one of three chrome fittings for the control levers wouldn't come, and I proceeded to ruin it.

[haysonj]

bump

[Andy4639]

First picture is the vacum valve that attaches to the controller in the dash it directs the vacum to the hot water valve and the flapper door on passenger side bottom of the cab and the flapper inside the cowl on the outside of the truck.
Second picture is the AC clutch cycle wiring that has the plunger attached to it. Goes behind the AC ducting inside the cab. The three prong plastic connector in second picture is the anti dieseling relay.

These should help!
My first picture even shows the vacum port that you posted but it's a 2 prong one with the tee inline. Either one will work.

[71CHEVYSHORTBED402]

That's awesome Andy, thank you. Incidentally, that harness per the original post may be for a CB radio.

[tommys72]

So my water valve is gone, and by the looks of my mess of vacuum lines, was bypassed. Is it possible to just remove the water valve and bypass it?

[tommys72]

in these pictures are the yellow circles the same "T"? where do the vacuum lines in the green circle go to? in the green circle i assume one of these lines go to port 3 on the control head vacuum switch. and how many lines are supposed to be on the vacuum actuator (air inlet valve)? The red circle in the pictures

port 2, if im reading all the above correctly, is t'eed (yellow circles) to both inside and outside vacuum actuators?

and port 1 goes directly to the water valve right?

truck is a 72 with factory ac.

[Andy4639]

Let me take shot.
The green circle is the vacuum ball that gives you reserve.
Line form intake vacuum goes in to ball and then line out goes to AC/Heater control head on dash. The line in the middle of each picture is the fire wall so the only tee's are inside the truck cab if using the 2 vacuum head.
If using the 3 vacuum head then you have one tee out under the hood.
With a two vacuum port it's the top looking at this picture.



Looking at the 3 vacuum port it's also the top.

[tommys72]

Ok so of your bottom pic, port 1 straight to water valve. Port 2 teed to both diaphragms . And port 3 straight to vacuum ball. Correct?

[Andy4639]

Originally Posted by tommys72

Ok so of your bottom pic, port 1 straight to water valve. Port 2 teed to both diaphragms . And port 3 straight to vacuum ball. Correct?

Yes starting at the bottom of the vacuum ports. Which when looking at the dash it would be #1 drivers side of dash #2 middle and #3 passenger side.

[tommys72]

Nice! Thanks Andy!

[tommys72]

So what determines using 2 or 3 ports? Haven't taken anything apart yet, but it seems mine is 2 port. Ac doesn't work, no water valve, and appears to be 2 ports. All the ac stuff is still there. Any of that sound right ?

[Kaptain Kadian]

Where is the vacuum source?

[tommys72]

Originally Posted by Kaptain Kadian

Where is the vacuum source?

At the rear of the intake manifold

[Andy4639]

Originally Posted by tommys72

So what determines using 2 or 3 ports? Haven't taken anything apart yet, but it seems mine is 2 port. Ac doesn't work, no water valve, and appears to be 2 ports. All the ac stuff is still there. Any of that sound right ?

If I remember right it's just by what year your truck is. I would have to look at the manual's and see which one is for what years. Those 2 pictures came out of each manual. 1 is a 69 and the other is a 71 but I don't remember which is which right off.