Muzzys AC hack for 4th gen ram

[Yeti15]

Hey guys,

Been searching all over and can’t seem to find quite what I’m looking for regarding the weak AC temps on my truck. Everything I come across speaks to 5th gen’s or the removal & replacement of the parts involved which I don’t need.

My truck -
A 2015 1500 bighorn with the standard ac (no dual climate). She’s got 162k trouble free miles on her and runs the R1243 Freon. AC temp runs 43-45 degrees with a clean cabin filter and recirc on. Never colder than that. Goal is to get 35-40 degree out the vents.

The background -
The ac has always been weak in temps and fan output compared to most other vehicles which most of us already know. Until recently it hasn’t been an issue for me worth digging into but now that I live in a much hotter area, it’s time to do something about it.

I’ve read all about the Muzzy AC hack and totally overlooked the compatible years (5th gen only) when I bought and installed it. Unsurprisingly no changes to my output temps but I did notice that my transmission took forever to heat up and barely got above 150. This was a mix of city and highway driving with about 40 miles on the highway at 70 and I couldn’t believe how cool the trans was running when I’m usually seeing 185-195 temps.

So I get back home, realize my mistake and also discover what I’ve come to find is the 3 way coolant valve which around 2017 was removed from the newer rams. I don’t know if they added something else in its place or took it out altogether in the 5th gen’s but please chime in if you do.

Here’s the question(s) -

1. Does anyone know if the 3 way coolant valve is completely out of the 5th gen’s or is there new system that serves the same purpose?

2. Can the 3 way valve be removed or bypassed in a way that won’t throw codes?

3. If I relocate the Muzzys valve and place it between the heater core and 3 way valve this should accomplish the intended goal of reducing temps via blocking off the heater core, correct? Does anyone know if or why this wouldn’t work?

4. Does anyone know if blocking the heater core and 3 way valve would cause issues with the valve itself or the transmission for that matter? How essential is this 3 way valve?

My thought process is that no issues would be caused by relocating the muzzy ball valve so it’s in between the heater core and 3way but after reading about the failures and other issues related to the 3 way valve I’m hesitant to possibly open a can of worms.

Any info, schematics of the cooling / trans system or alternatives to improve ac temp please share!

Thanks!

 

[Wild one]

Hey guys,

Been searching all over and can’t seem to find quite what I’m looking for regarding the weak AC temps on my truck. Everything I come across speaks to 5th gen’s or the removal & replacement of the parts involved which I don’t need.

My truck -
A 2015 1500 bighorn with the standard ac (no dual climate). She’s got 162k trouble free miles on her and runs the R1243 Freon. AC temp runs 43-45 degrees with a clean cabin filter and recirc on. Never colder than that. Goal is to get 35-40 degree out the vents.

The background -
The ac has always been weak in temps and fan output compared to most other vehicles which most of us already know. Until recently it hasn’t been an issue for me worth digging into but now that I live in a much hotter area, it’s time to do something about it.

I’ve read all about the Muzzy AC hack and totally overlooked the compatible years (5th gen only) when I bought and installed it. Unsurprisingly no changes to my output temps but I did notice that my transmission took forever to heat up and barely got above 150. This was a mix of city and highway driving with about 40 miles on the highway at 70 and I couldn’t believe how cool the trans was running when I’m usually seeing 185-195 temps.

So I get back home, realize my mistake and also discover what I’ve come to find is the 3 way coolant valve which around 2017 was removed from the newer rams. I don’t know if they added something else in its place or took it out altogether in the 5th gen’s but please chime in if you do.

Here’s the question(s) -

1. Does anyone know if the 3 way coolant valve is completely out of the 5th gen’s or is there new system that serves the same purpose?

2. Can the 3 way valve be removed or bypassed in a way that won’t throw codes?

3. If I relocate the Muzzys valve and place it between the heater core and 3 way valve this should accomplish the intended goal of reducing temps via blocking off the heater core, correct? Does anyone know if or why this wouldn’t work?

4. Does anyone know if blocking the heater core and 3 way valve would cause issues with the valve itself or the transmission for that matter? How essential is this 3 way valve?

My thought process is that no issues would be caused by relocating the muzzy ball valve so it’s in between the heater core and 3way but after reading about the failures and other issues related to the 3 way valve I’m hesitant to possibly open a can of worms.

Any info, schematics of the cooling / trans system or alternatives to improve ac temp please share!

Thanks!

You can bypass the 3 way valve with no issues,as long as you leave it plugged in. I bought the molded heater hoses for an older truck with the 5/6 speed transmission,and got rid of the heater hose mess on my 14. Why not buy yourself a couple of hose clamps and install them on the heater hoses by the firewall.That's all i did on all 3 of my Chryco products when it was hot out.
I use these,as they're lighter then actual clamp off pliars,so you don't have to worry about hurting the heater core,they're easy to install for hot weather and easy to remove for cooler temps.

Amazon.com

 

[TC]

4th gen Ram. Same problem until I placed a ball valve in the hose leading to the heater core and now have cold AC. 34 degree temps coming out of AC vent.

 

[Yeti15]

You can bypass the 3 way valve with no issues,as long as you leave it plugged in. I bought the molded heater hoses for an older truck with the 5/6 speed transmission,and got rid of the heater hose mess on my 14. Why not buy yourself a couple of hose clamps and install them on the heater hoses by the firewall.That's all i did on all 3 of my Chryco products when it was hot out.
I use these,as they're lighter then actual clamp off pliars,so you don't have to worry about hurting the heater core,they're easy to install for hot weather and easy to remove for cooler temps.

Amazon.com

Thanks. I’ve got a set of similar clamps and will likely go that route for now. I’ve just been worried about the 3way valve and it’s strange to me how some seem to have it and some don’t.

 

[StateOfMind]

You can bypass the 3 way valve with no issues,as long as you leave it plugged in. I bought the molded heater hoses for an older truck with the 5/6 speed transmission,and got rid of the heater hose mess on my 14. Why not buy yourself a couple of hose clamps and install them on the heater hoses by the firewall.That's all i did on all 3 of my Chryco products when it was hot out.
I use these,as they're lighter then actual clamp off pliars,so you don't have to worry about hurting the heater core,they're easy to install for hot weather and easy to remove for cooler temps.

Amazon.com

Slick. I was unaware of these, and look far less damaging then the vise grip style clamps. Just ordered some, thank you for the education, and for lightening my wallet

 

[Yeti15]

4th gen Ram. Same problem until I placed a ball valve in the hose leading to the heater core and now have cold AC. 34 degree temps coming out of AC vent.
View attachment 550235

Interesting on your 14…. I’m basically looking at the same thing but I notice you don’t have the 3 way valve.

In my image, the 3way valve is circled yellow and my hot water is indicated by the red lines which go from the firewall, hit the 3way and then run to the water pump with another line coming out the bottom of the 3way. I installed my ball valve in between the water pump and 3way as shown so I’m thinking I just need to relocate it.

Curious if you have the 5.7 and tow package?

 

[Wild one]

Interesting on your 14…. I’m basically looking at the same thing but I notice you don’t have the 3 way valve.

In my image, the 3way valve is circled yellow and my hot water is indicated by the red lines which go from the firewall, hit the 3way and then run to the water pump with another line coming out the bottom of the 3way. I installed my ball valve in between the water pump and 3way as shown so I’m thinking I just need to relocate it.

Curious if you have the 5.7 and tow package?

The 5 and 6 speed trucks don't have the 3 way valve,only the 13 to 16 trucks with the 8 speed have the 3 way valve,they did away with the 3 way valve after that.

 

[Wild one]

Thanks. I’ve got a set of similar clamps and will likely go that route for now. I’ve just been worried about the 3way valve and it’s strange to me how some seem to have it and some don’t.

You can bypass the valve.As long as you leave it plugged in,it won't throw a code or check engine light

 

[Yeti15]

The 5 and 6 speed trucks don't have the 3 way valve,only the 13 to 16 trucks with the 8 speed have the 3 way valve,they did away with the 3 way valve after that.

Yep that makes the most sense then. Forgot about the different trannys in the earlier models. Thanks for the feedback, I’m going to get everything corrected and will report back with findings or issues so hopefully this will help a future member.

 

[jws123]

I swapped out my freon from 1234yf back to r134 using adapters that are sold online been a year no issues ice cold just like my old 2011 was.

 

[TC]

My truck is a 2016 Laramie with 8 speed tranny. Tow package included. Maybe they removed the three way valve on 16 models.

 

[Wild one]

My truck is a 2016 Laramie with 8 speed tranny. Tow package included. Maybe they removed the three way valve on 16 models.

Some of the real early 16's still had the valve,somewhere in 16 they removed the valve. My neighbours early built 16 Sport still has the valve,but it's also a Canadian spec truck,and FCA was famous for dumping old parts into Canada,lol.

 

[Wild one]

If you guys are bored,here's a long thread on how Khris/CrazyKid and i deleted the thermal management unit.That was before Jesse Caulk had his bypass out,which is a better way to go.

RevMax 8 speed thermostat bypass

I know there's a few guys running Rev Max's bypass.How do you like it,and was it very difficult to install? 2014-2020 Dodge Ram 8HP70, 8HP75 Transmission Cooler Thermostat Bypass | Revmax Converters

www.ramforum.com

 

[Yeti15]

Welp, just to provide an update for everyone. Before cutting into the hoses and reinstalling the ball valve I decided to do some double checking/testing. I took a hose clamp and placed it on the line that runs from the firewall to the 3valve and drove around for a few days with no improvement or change in output ac temp. I then removed said clamp and placed it on the hose next to it that runs from firewall direct to water pump. It appeared that this did the trick but not really. I’ve only noticed a temp drop when I’ve got the fans maxed out and driving down the highway but it still doesn’t go below 40-42 degrees. Slowing the fan speed or driving through town provides no difference and I get the same temps as before. Really stumped here and wish I had a solution last week when we got hit with a heat wave. AC was pathetically inadequate.

Unless there’s other ideas it looks like I’m SOL. My only other thoughts are perhaps my hose clamp is still letting too much hot coolant through so I could try really clamping that sucker down or I should just dump the Freon and replace with 134a when I visit my pops this year.