04fxdwgi
Senior Member
- Joined
- May 19, 2023
- Posts
- 1,825
- Reaction score
- 3,847
- Location
- Coastal NE North Carolina
- Ram Year
- 2016 1500 Sport
- Engine
- 5.7 Hemi

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Years ago alot of vehicles used to use a manual valve in the heater core feed line that used a cable connected to the dash heater controls to manually shut off the flow to the heater during the summer months.That'd be your simplest,least trouble prone set up. I've actually done that trick years ago on a couple of my old vehicles,i just used a Choke Cable to control the underhood valve,and it worked good,and was simplicity onto itself to build and use,and never gave any trouble.Pull the cable to shut off flow,push the cable to restore flow to the heater core.Infinitely adjustable and totally reliable.Okay, you are definetely right in the way that troubleprone item is not a brilliant idea.
I will revise the concept once again on the weekend...
Thank you for your time!
PS. An illustration of the initial design:
View attachment 584289
Couldn't tell you, i've replaced a few,because they were throwing codes,but never did take any of them apart to see what was wrong with them,always gave them back to the vehicle owners to do whatever they wanted with them.But they're plastic,and a plastic based valve never seems to last. Ram only used them for a couple years though,before doing away with them,so i'm guessing they were replacing them under warrenty,and decided to simplify the system,and take the trouble prone 3 way valve out of the system,reducing their warrenty costsBTW what is the main malfunction reason in the stock RAM 3-way valve? Poor sealings / poor wiring / material degrading / whatsoever?
There have been quite a few I've read about that either water or coolant was found in the electronics compartment. The valves are not as trouble prone as some on this forum make them out to be.BTW what is the main malfunction reason in the stock RAM 3-way valve?
A simple ball valve can be completely modulated,and would do exactly what he wants it to do if it was set up with a cable or linear actuator,and would be simplicity onto itself to incorporate into a heater line.There have been quite a few I've read about that either water or coolant was found in the electronics compartment. The valves are not as trouble prone as some on this forum make them out to be.
As for your quest of using this three-way valve to modulate heat, the biggest factor is usually sizing in relation of flow of the valve itself. Linear movement of the valve doesn't equate to linear output from the coil. Modulation of a 3-way even poorly sized still works better in most cases than on/off but with your application of turning the heater core off it's not a huge advantage.
Not sure if design is amined at the same system as my 2013 Ram 3.6L but the 3 way coolant valve is used to cool the transmission. The computer commands the valve to open or close depending on the temperature of the transmission. With a scanner, you can see the desired degree of open on the valve and actual degree of open.Okay, you are definetely right in the way that troubleprone item is not a brilliant idea.
I will revise the concept once again on the weekend...
Thank you for your time!
PS. An illustration of the initial design:
View attachment 584289
I'm glad I removed the coolant lines from my 3-way valve/TMU. No danger of intermingling fluids.It's also used to heat a cold transmission, if needed.
The "cooler / heater" is so easily replaced / bypassed with an aircooled cooler up front and a thermostatic mechanical valve. That would eliminate the possibility of a cooler going bad and leaking coolant into the trans, or trans fluid into the coolant.