I did HorsePowerJunkies air conditioning mod the other day (using the recirculating Ford Ranger heater hose shutoff) and I can tell you this mod has made my truck vent/air conditioning system really efficient. I went to the lake yesterday and ran just the vent going to the lake (prior to this the vent was worthless above 60 degrees (the air coming out was too warm). Coming home it was above 100 degrees and I ran the air conditioning with the thermostat at the mid-point (right where the red overlaps the blue on the thermostat - the 12 o'clock setting)...the air conditioner nearly froze us out! I use to have to run the AC thermostat at about the nine oclock setting. I hooked the valve to the red vacuum hose behind the glovebox and it shuts coolant off in vent, AC, and MAX AC. Total cost $25 (valve, five feet of vacuum hose and t-fitting).

 

Heeey there, what is this mod?

 

Can you post pics?

 

Please tell us more....... I'm in South Louisiana sweating my you know whats off..........

 

He went to a little more trouble than really necessary. A quick fix is a simple high quality brass on/off valve in the hot coolant line entering the ac/heater box at the firewall. I have not looked cuz I have not even used my air yet this year but have used this low budget fix on other vehicles over the years.

 

You cut both the supply and return lines to the heater core just in front of the firewall. Then install Autozone part # 74809 (it fits a Ford Ranger) heater control valve (the valve works no matter which way it is installed). The valve, when actuated by vacuum cuts the flow of hot water to the heater core and sends it back to the engine. Coonect a vacuum line to the valve and run it through the firewall (there is a plug near the floor which you can get it through without drilling). Pull the rubber bumpers on the glove box inward and the glove box will hang down. Look at the left and you will see a vacuum valve with a bunch of vacuum lines coming to it. Cut the RED hose, put in a vacuum t-fitting and connect the hose from the heater control valve you just installed. Now, any time you move the control on the dash to VENT, AC, or MAX AC the hot water won't flow to the heater core. This will make the AC much colder (some have reported 10-15 degrees colder). I can see many times when I use to have to run AC, I will be able to just run the vent and when I do have to run AC, I can set the thermostat much higher (warmer) and yet be cooler...this mod will pay for itself! Total time for mod: 30-45 minutes...

Parts you will need:

1 - Autozone #74809 heater valve

5' of 3/16" vacuumline

4 - 7/8 or 1" screw clamps

1 - vacuum T-fitting

 

I like the idea of diverting the hot coolant from the core and sending it back. I may look at the unit or fabbing up some sort of manual system of doing it from underhood for the summer months, then opening up for other times. I'm not big on messing with the stock control or adding another potential vacuum leak. That is a good idea though. Thanks.

 

I have no knowledge of the coolant circulation system on these trucks, but over the years I have never had a problem with just stopping it at the inlet and calling it a day.

 

Alright, I just took a couple of pictures...

Here is the picture of the valve installed on the truck...remember, makes no difference how you hook it up (vacuum valve facing either way, it will work).


And here is the vacuum t-valve installed behind the glove box. The red vacuum line will give hot water shut-off at ALL settings to the left on the controlled (VENT, AC, or MAX AC):



Hope this helps....Neal

 

is there any way to rig this so it only comes on w/ AC and MAX AC?

 

I know there is a way to hook it up for MAX AC only...I think it is the white vacuum line you splice into. Someone ought to confirm though...I seem to remember that Bob Reilly at Dieselsite.com hooks his system up to only work at MAX AC setting.

 

Do you have to get your AC charged again after doing this mod? Can you send us a link to where you first saw this?

 

Sorry I can't find the link...the guy who I first saw do the mod is known as "horsepowerjunkie", but I don't where I saw it...I just stored the info away because I thought it was a simple solution to a problem.

No you never enter the air conditioner circuit at all...This mod simply cuts the flow of hot water to the heater core whenever you turn the the selector to VENT, AC, or MAX AC.

One note that I have just become aware of. The air conditioning system in our trucks does not use a thermostat to adjust air conditioner air temperature. When you turn the selector for temperature, you are just allowing air that has gone over the heater core to mix with the air conditioning air. Thus if you make this mod, you no longer can adjust the temperature of the air from the air conditioner because there is no flow of hot water to the heater core. I control temperature with the fan...but man does the VENT setting work good now and the air conditioner is at least 15 degrees colder .

 

a $2 manual shut off valve is just as effective.

 

Not to mention a whole lot less trouble. Think I first did it on a 1984 E150, worked fine then and I'll bet it is still working today, but I doubt if that van is.