Is there a valve that controls the circulation of the coolant through the heater core? How does this affect the performance of the air conditioning system?

 

If you do a search,You will read shutting the flow of hot coolant off will lower the AC temps,you can use a simple 1/4 turn valve if you don't mind opening the hood to change from heat to cooler AC,or get a vacuum controlled valve that shuts off with
AC controls.,some of the vacuum valves never performed well,I don't prefer colder AC so somebody will chime in on the better valve choices.

 

I had the Diesel Site vacuum valve, it was not good and met the face of a 3 lbs hammer.

I installed the Ranger/Excursion vacuum valve and have been very pleased with the results.

Other have installed manual ball valves because they reported the Ranger/Excursion valve leaking after a while.

Either way, the A/C is much cooler now and I am grateful. No adverse effects on engine performance or ability to keep itself cool.

 

 

I have two setups put together so far....

Alpha using 4 ball valves in "H" format
Bravo using 2 3-way ball valves also in "H" format....

seeing this thread as I had just replied to two threads just now... makes me think I should, at least post a pic of each in partial assembly....just not installed yet....

 

Go to your big box store, get a 3/4" female water valve (should be a 1/4 turn ball valve), get 2 adapters to go to a 5/8" hose and then clamps. Install it in the supply side heater hose. You'll have to cut it and probably take out a little bit for the length of the valve ~ maybe not. On my truck I had to put tape around it to insulate it to keep it from touching any electrical connection. Dropped the air temperature out of the air conditioner by 15 degrees immediately. Look for the correct freon pressure on the low side from the some of the vehicle forums. My truck is set at the minimum ~ 45.

 

Some trucks already have a shutoff of sorts...I believe it is 2002 up. It shuts off most of the coolant flow when the AC is switched to MAX. It is designed to allow a trickle to still flow, supposedly to keep the heater core from getting stagnated with corrosion causing coolant. I am on the fence on this one because I have a 2002 and the AC is usually ice cold with no issues. The only time It does not seem cold enough is when stuck in traffic for extended periods, like more than 15 or 20 min at a time without moving. The rest of the time it freezes me out.

 

"The only time It does not seem cold enough is when stuck in traffic for extended periods, like more than 15 or 20 min at a time without"

I can't tell you moving to an area that has no traffic jams, well at least after the road project is complete, makes life so much more enjoyable.
Lived and worked in Sillycone valley way too long.

 

It's not bad like that here, what I am referring to is international border crossing which has taken up to 2.5 hours at times. At least we only do that one or two times a year. Other than that it's the occasional wreck on the interstates

 

bigb56, Just that I noticed you ware in AZ. I was thinking along the lines of Phoenix or Tuscon area. My brother lives in Green Valley.

 

I'm just up the road in Tucson, traffic not nearly as bad as PHX or some of the West coast cities. Worst is when there's a wreck on I-17 in the mountains blocking both lanes and there's nowhere to go. A few years ago a truck loaded with rebar overturned and we heard there was a 7 hour delay for the unfortunates who got stuck behind it. There's just nowhere to go, exits are few and far between.

 

I wish mine was like that. The one that comes with the truck only activates in MAX A/C and (at least on mine) definitely seemed like more than a "trickle"...

So I installed a Ranger valve...and it leaked. So I installed another Ranger valve...and it leaked.

So I installed a ball valve instead. I'm not keen on going under the hood every time to operate it but it works great and doesn't leak.

The best part is that it works in all settings. It definitely makes a difference but I've got to make sure it's warm out though because when that ball is shut there is no heat AT ALL. I have spent my share of days in the blistering heat of the Persian Gulf so I prefer a chillier atmosphere anyway.

 

There are a couple of ways you can tap into your vacuum system to operate a vacuum controlled Ranger valve which will give you various levels of temperature control while using the A/C. I opted for the configuration which gives me full range temp control unless I have the A/C on MAX, then it's just "as cold as it can get"! I made this modification about 7 years ago and it's all still running great. I've attached a write-up I pulled together from others' expertise which outlines your various options. The second PDF explains how to shim your A/C clutch, in the event you ever need to do that as well.