HMMWV Heater electric actuator replacement

[Dave2018]

Trying to get better part numbers for the electric actuator on the heater. don't need the 400.00 valve/hose/actuator combo.
will be looking to replace just the actuator with oem or equavilant part. I attached a pic of my label but its torn and missing a few numbers. Have 749235H6?? so far.
will post the replacement part here even if its an aftermarket actuator. Thanks.

After further looking I found out Thermotion is out of business. Dang X2

 

[Coug]

I believe the typical replacement is to install the manual valve from the earlier trucks.

 

[Dave2018]

I believe the typical replacement is to install the manual valve from the earlier trucks.

I may have to do that. Kind of short on time, last repair took me forever.
Thanks,
Dave

 

[Coug]

I may have to do that. Kind of short on time, last repair took me forever.
Thanks,
Dave

if really short on time, some people have gone to the local hardware store, purchased a 1/4 turn type ball valve, and I believe it was 5/8" hose fittings, and just made it so you open up the hood to turn heat on or off.
You'll need to verify the hose inside diamter first as I might be wrong on that 5/8"

 

[Dave2018]

if really short on time, some people have gone to the local hardware store, purchased a 1/4 turn type ball valve, and I believe it was 5/8" hose fittings, and just made it so you open up the hood to turn heat on or off.
You'll need to verify the hose inside diamter first as I might be wrong on that 5/8"

I'm pretty good for turnign it on and off, The lever moves easy with the actuator moved. But yesterday I needed the heat in am and ac in pm. so I have to left the hood and toggle the lever. Its not that bad just be nice to get it fixed.
thx, dave

 

[86humv]

I have a few of those actuators without valves I tested last week....4 of 5 of them checked out good.
$40 ea.

 

[TOBASH]

I just used a unit from Ama$on.

Replaced and zip tied closed position.

RWH has mentioned in the past to me that he installs old style cable push pull knobs to make these more reliable units function manually.

[EDIT - I added pics of my install and how the area is obscured by the air intake horn.]

 

[DREDnot]

This is what ive done on my current truck. Old style manual valve and cable actuator.

 

[Dave2018]

I have a few of those actuators without valves I tested last week....4 of 5 of them checked out good.
$40 ea.

I will buy one of those from you, Dave

 

[Dave2018]

I just used a unit from Ama$on.

Replaced and zip tied closed position.

RWH has mentioned in the past to me that he installs old style cable push pull knobs to make these more reliable units function manually.

[EDIT - I added pics of my install and how the area is obscured by the air intake horn.]

I may end up doing the cable, going to try replacing the actuator with a take out first.

 

[TOBASH]

I may end up doing the cable, going to try replacing the actuator with a take out first.

If you look closely you will see that I just zip tied my unit closed. If I ever need it, I’ll cut the zip tie and zip tie a new one into place keeping the valve open.

Eventually, perhaps I will add a cable, but it is very low on my priority list because the truck lives in a warm area.

 

[Retiredwarhorses]

I may end up doing the cable, going to try replacing the actuator with a take out first.

Here’s the problem, the OEM valve is garbage, even when working they dont stop the flow of hot water into the evaporato/heater, thus you have Luke warm A/C, if you only care about heat? You don’t need the valve.

 

[Dave2018]

Here’s the problem, the OEM valve is garbage, even when working they dont stop the flow of hot water into the evaporato/heater, thus you have Luke warm A/C, if you only care about heat? You don’t need the valve.

Here in Texas we do care about the ole ac.....specially old folks. Been working in heat my whole life. time to relax just a tad bit. : )

 

[KKroger]

Short on Time, do you need it ON or OFF? because you can bypass the valve and just run heat until you can do better... takes maybe a foot of 5/8 heater hose... If you want it OFF then bypass the heater and just return the coolant back to the engine... easy.

 

[Dave2018]

Short on Time, do you need it ON or OFF? because you can bypass the valve and just run heat until you can do better... takes maybe a foot of 5/8 heater hose... If you want it OFF then bypass the heater and just return the coolant back to the engine... easy.

Thanks for the reply. I'm in the middle now of either bypassing or putting in a 998 heater pull cable.
Thanks,
dave

 

[DREDnot]

While the pull cable with metal valve is most convenient, the valve has a less than perfect seal and does not stop the hot water 100%

If you only need heat seasonally and maximum A/C the rest of the time I get best results using a manual ball valve for complete sealing.



The original electric ones are junk and even if you twist it closed manually the butterfly inside is usually disintegrated into numerous pieces.

 

[TOBASH]

While the pull cable with metal valve is most convenient, the valve has a less than perfect seal and does not stop the hot water 100%

If you only need heat seasonally and maximum A/C the rest of the time I get best results using a manual ball valve for complete sealing.

View attachment 959527

The original electric ones are junk and even if you twist it closed manually the butterfly inside is usually disintegrated into numerous pieces.

View attachment 959529

Good points…

100% correct about not closing all the way.

100% correct about check valve having the ability of closing completely.

 

[Dave2018]

While the pull cable with metal valve is most convenient, the valve has a less than perfect seal and does not stop the hot water 100%

If you only need heat seasonally and maximum A/C the rest of the time I get best results using a manual ball valve for complete sealing.

View attachment 959527

The original electric ones are junk and even if you twist it closed manually the butterfly inside is usually disintegrated into numerous pieces.

View attachment 959529

That looks like the inside of our chillers at work. Before I got here the city forgot to treat the condenser water for 4 years.....
Thanks for that. Dave