Vacuum Controlled Heater Core Valve

[Bruno2]

Somewhere in the mid 80's the Ford Ranger (little Ranger not big Ranger) used a vacuum controlled heater core shut off valve that was actuated whenever the AC was set to max. I am assuming it is supplied by a split going to the damper door that shuts with vacuum whenever the AC control is set to max.

What year trucks used this valve?

Where is the vacuum line on our trucks that operates the damper door? Is it color coded?

[Gary Lewis]

I'll look through the catalog, but it will take some time to track it down.

[85lebaront2]

I'll look through the catalog, but it will take some time to track it down.

Chrysler used a similar one and my son had a failed on on one of the delivery trucks at AutoZone when he was commercial manger They had no listing, Ford wanted around $75 for it, he grabbed a Chrysler one out of stock, it sat upside down but worked and fit perfectly. The K-cars used one with the lines essentially straight across, bypassed the coolant when off for manifold heat on the 2.2/2.5L engines. Mounted close it would give instant heat when opened.

White or black/white should be recirc door close.

[Gary Lewis]

I've found lots of references to F87Z-18495-AA, which is also said to be Ready-Aire by Transpro 4-Seasons #74809. Here's a link to Air Conditioning Mod - Ranger Shutoff Valve where they talk about that valve and have pictures thereof, but it is a 4-port valve that recirculates water to the engine.

Since Ford rarely changes the basic part number I then turned to the 1980 - 89 parts catalog looking at "18495". Turns out that they had a valve for the Ranger ® in the 80's:

Searching for YG-264 got me the following picture here, although it is said to be E4TZ 18495-A:

EDIT: THIS VALVE WILL NOT WORK AS VACUUM OPENS IT!

[grumpin]

I used a NAPA as shown in the link.

Equivalent to a Motorcraft YG350.

Hooked in the Max A/C vacuum line on my Bronco. I might put one on the F250.

https://www.napaonline.com/en/p/BK_6601294

[Gary Lewis]

I used a NAPA as shown in the link.

Equivalent to a Motorcraft YG350.

Hooked in the Max A/C vacuum line on my Bronco. I might put one on the F250.

https://www.napaonline.com/en/p/BK_6601294

The problem we have is that we would like the valve to work in both Vent and Max A/C. Unfortunately our control doesn’t give a vacuum signal for both of those situations and not others, as shown by a table from the 1981 shop manual, below.

My plan is to use connection #1 on the HVAC control, which isn't used. As shown below it provides vacuum on both Vent and Max, but not on Norm. The plastic on the control isn't drilled, and there's no hose on that port of the connector, but I think that should be easy to fix However, that is for a 1980/84 control, and I haven’t looked at a 1985/86 control to see if that is possible with them.

[85lebaront2]

The problem we have is that we would like the valve to work in both Vent and Max A/C. Unfortunately our control doesn’t give a vacuum signal for both of those situations and not others, as shown by a table from the 1981 shop manual, below.

My plan is to use connection #1 on the HVAC control, which isn't used. As shown below it provides vacuum on both Vent and Max, but not on Norm. The plastic on the control isn't drilled, and there's no hose on that port of the connector, but I think that should be easy to fix However, that is for a 1980/84 control, and I haven’t looked at a 1985/86 control to see if that is possible with them.

Gary, if you could do like the 1973-79 trucks did, there was a small plunger type valve on the temperature lever, actually 2 if I remember correctly. on full cold in A/C mode, it operated the recirc actuator and shut off the water flow, the second one on the early models put the water in a half flow mode. It worked very well considering on mine the case and the 390 seemed like they wanted to mate with each other.

If you used one of those valves, you could use the recirc to shut it off, and the panel vacuum to put it in half flow, another thought, use a 3 port solenoid vacuum valve to keep the water flow off in panel but enable it if the compressor circuit is live in A/C norm mode for temperature control. A microswitch on the temperature lever could keep the vacuum on to the water valve in full cold position.

FWIW, the later system does not seem to have a problem with cooling even after a hot soak with a 460.

[Gary Lewis]

Gary, if you could do like the 1973-79 trucks did, there was a small plunger type valve on the temperature lever, actually 2 if I remember correctly. on full cold in A/C mode, it operated the recirc actuator and shut off the water flow, the second one on the early models put the water in a half flow mode. It worked very well considering on mine the case and the 390 seemed like they wanted to mate with each other.

If you used one of those valves, you could use the recirc to shut it off, and the panel vacuum to put it in half flow, another thought, use a 3 port solenoid vacuum valve to keep the water flow off in panel but enable it if the compressor circuit is live in A/C norm mode for temperature control. A microswitch on the temperature lever could keep the vacuum on to the water valve in full cold position.

FWIW, the later system does not seem to have a problem with cooling even after a hot soak with a 460.

Bill - I think I follow your logic, but that looks like a lot of work and fabrication. And if my idea of drilling the unused #1 port works I think it would be a lot easier.

Ok, maybe it is time for an aside on the huck-parting party and see if my idea works. I’ll have a few minutes this afternoon between church activities to see how hard it would be, and maybe even attempt it.

[grumpin]

Bill - I think I follow your logic, but that looks like a lot of work and fabrication. And if my idea of drilling the unused #1 port works I think it would be a lot easier.

Ok, maybe it is time for an aside on the huck-parting party and see if my idea works. I’ll have a few minutes this afternoon between church activities to see how hard it would be, and maybe even attempt it.

I see. I have a electrically operated vacuum switch on standby, in case I wanted to go that route.

Then I could actuate it anytime I wanted.

I think the F250 is much better as lebaron said (I think), cools really well. I was assuming the "bigger" tubed A/C works better.

If drilling that control will work, that is cool!

[Gary Lewis]

I see. I have a electrically operated vacuum switch on standby, in case I wanted to go that route.

Then I could actuate it anytime I wanted.

I think the F250 is much better as lebaron said (I think), cools really well. I was assuming the "bigger" tubed A/C works better.

If drilling that control will work, that is cool!

Ok, I think I have the answer: The 1980-84 Integral A/C controls can easily be adapted to provide vacuum to a valve in Vent and in A/C Max. But the 1985-86 Integral A/C controls cannot. However, the earlier controls may be able to be used in the later trucks. Read on....

I'm going to show you why and how, below, but want to write it up for the website and need your guidance on how/where to do that. My thinking is to put a tab called something like Improvements on the HVAC/Integral A/C page, and then show the info below on that tab. Plus, I'll place a link in the Resources folder here on the forum to that page so people can more easily find it. Thoughts?

As for why and how the 1980-84 controls can be modified to control a valve, here's the table from the 1981 shop manual again. Notice that the vacuum source is port 7, and that port 1 isn't used. However, it has vacuum to it in both the Vent and A/C Max positions, but none other, which is perfect for controlling a valve closing off the flow of hot water to the heater core as we would have no heat in Vent or A/C Max, but heat in all the other positions.

And here are the ports on the switch, with port 1 being open.

But, here's the connector for the vacuum harness, and you can see that port 1 doesn't have a hose on it. In fact, it is blanked off.

Here's a side view of that connector and you can see that there's plenty of room to drill the connector and insert a piece of either hard plastic tubing or a piece of brass tubing, onto which you can slip a vacuum hose.

But, why can't that be done on the 1985-86 Integral A/C controls? That's because the two unused ports, #'s 5 & 6, are not connected to vacuum in Vent and A/C Max. They are only connected to each other, and that doesn't help. So, what can be done? Change out the 1985-86 control w/a 1980-84 control. But that will also mean you'll need the 1980-84 vacuum harness and will have to change the pinout on the blower switch connector. And, that won't work with a 1985-86 truck with electric fuel pumps and dual tanks as the tank switch is much more complex than the earlier switch. However, I'll check to see if that switch can be swapped, which would solve the problem.