Anyone added a "Mojave" heater to their Humvee ?

[JoeJrTheBarber]

Evening,

My new to me Humvee is a blast to drive but this cold ass Chicago winter is really taking the fun outta it as a freeze my balls off with the sad excuse of a heater these things come with. Even on full bore the thing does generate heat but the truck just doesn't retain it to make the truck fun to drive. Plus having the soft top, doors, and back rear curtain with a 2' gap isn't really helping retain the heat the heater does give off. a full "hard top" conversaion is in the works but who knows when that will all be sourced and installed..

So, my question: Have any of you dudes replaced and or added a Mojave style heater setup in your rigs ? The Mojave is from Flex-a-lite and is a pretty rad / compact setup that takes just two coolant lines and a 12volt source to get going and blows a said 14,000BTU of heat . An before someone posts it I am aware the trucks run on 24volts but I already have a 12volt breaker to wire stuff like this into. Not sure but I'm guessing the stock setup / heater doesn't come close to the 14,000 BTU claim of the Mojave but don't quote me on that as I am not 100% sure. I was thinking for ease of packaging and to not have to re-invent the wheel (so to speak) to add the Mojave under the left rear seat and use it along with the stock setup. The Mojave would have its own separate control for fan speed, which I could control and vary depending on if I had rear passengers or not (usually don't).

Anyone done something like this ? Thoughts ?

 

[Wire Fox]

This is more power draw than the typical 12V accessories run in these. I don't see any reason why this couldn't work if you were going to fab up your own brackets and controls, but be careful not to unbalance your batteries and cause premature failure of your batteries and/or alternator. A load balancer or religious battery maintenance would be a good idea when using this.

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[JoeJrTheBarber]

This is more power draw than the typical 12V accessories run in these. I don't see any reason why this couldn't work if you were going to fab up your own brackets and controls, but be careful not to unbalance your batteries and cause premature failure of your batteries and/or alternator. A load balancer or religious battery maintenance would be a good idea when using this.

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I hear ya on the load situation. My truck is going under the knife in a few weeks and my buddy who is helping me wire the thing is a genius when it comes to wiring and the such. We are using a 24v-12v step down convertor and a 3rd battery setup just for the 12volt items we are adding to the truck.

 

[Dock Rocker]

Have you cleaned out your heater core and flushed out your cooling system? Many people run in similar temps without issue.

Also put some roll insulation in the top and cut some pipe insulation longways and put it between your bed floor and your rear curtain. That will help with the draft.


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[JoeJrTheBarber]

Have you cleaned out your heater core and flushed out your cooling system? Many people run in similar temps without issue.

Also put some roll insulation in the top and cut some pipe insulation longways and put it between your bed floor and your rear curtain. That will help with the draft.


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I haven't cleaned out the cooling system as of yet, but its on the list when the truck goes in for its "upgrades"..
Never thought about the roll insulation idea, makes sense !

 

[Dock Rocker]

I haven't cleaned out the cooling system as of yet, but its on the list when the truck goes in for its "upgrades"..
Never thought about the roll insulation idea, makes sense !

A pool noodle works to but it doesn’t have quite the cool factor.


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[Dock Rocker]

Jeff did a video of the top insulation he did.

https://youtu.be/FGB-sPBLlW0


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[Action]

Get some 1 1/2" thick black foam and cut to fit upright in the rocker panels. Do you have all the floor padding in place? Did you say you want to put it under the rear left seat? I assume your base is a "box". Are you going to cut holes for the heat to get out? What about flow for air to get into it?
I replaced the heater core in my '85 with an early H1 core. It was bigger but still fit in housing. That helped a lot. Also, check to see if any of your hoses are rotted and have holes in them.

 

[Wire Fox]

A pool noodle works to but it doesn’t have quite the cool factor.


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Just make sure you buy a forest green pool noodle and peel the sticker off. If anyone asks why you have a pool noodle in your HMMWV, deny everything.

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[Dock Rocker]

I forgot one easy thing. Make sure the valve that the leaver in the cab actuates is actually opening fully. If it’s not opening you aren’t getting full coolant flow to the heater core.


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[karlsmith]

My new to me Humvee is a blast to drive but this cold ass Chicago winter

With the little snow we've had in Chicago this winter, Streets and Sans has been laying the salt down thick as a blanket. I'm not driving mine, just for that reason. As for your weak heater, the first thing I did when I got mine last year was the cooling system. I know it's on your agenda, and it's really going to help out for the one week of 90 degree weather we'll get this summer. I dig the heater upgrade idea. I was thinking the same thing, but for the summer with a micro-AC unit that they use for a porta john.

 

[NormB]

I forgot one easy thing. Make sure the valve that the leaver in the cab actuates is actually opening fully. If it’s not opening you aren’t getting full coolant flow to the heater core.
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And make sure the outside vent is closed. Finally occurred to me to do this. Less forced air cooling equals more heat.

 

[JoeJrTheBarber]

Get some 1 1/2" thick black foam and cut to fit upright in the rocker panels. Do you have all the floor padding in place? Did you say you want to put it under the rear left seat? I assume your base is a "box". Are you going to cut holes for the heat to get out? What about flow for air to get into it?
I replaced the heater core in my '85 with an early H1 core. It was bigger but still fit in housing. That helped a lot. Also, check to see if any of your hoses are rotted and have holes in them.

I have only owned the truck for alittle over a month and the Chicago cold has kept me from messing around with it too much in the garage. Guess my first step is to get some insulation / dynamat and go that route first, then I can worry about replacing / adding a secondary heater. Like I said the factory heater does blow heat, it just could have alittle more output in my opinion.

 

[JoeJrTheBarber]

And make sure the outside vent is closed. Finally occurred to me to do this. Less forced air cooling equals more heat.

In what position on the heater controls "closes" the outside vent ?

 

[porkysplace]

In what position on the heater controls "closes" the outside vent ?

It's most likely covered in the -10 TM.

 

[NormB]

In what position on the heater controls "closes" the outside vent ?

The one that blocks out the light (and outside air, coincidentally).



I just reread your post. It’s not the HEATER, but the VENT. On the right side of the commander’s seat footwell. Look outside the truck forward of the door and you’ll see a couple of louvers. INSIDE is a control plate to regulate fresh air.

I knew it was there, I’d just forgotten to close it off when the weather changed around November, shut it off last week when it was around 5F outside.

Big difference.

 

[JoeJrTheBarber]

The one that blocks out the light (and outside air, coincidentally).



I just reread your post. It’s not the HEATER, but the VENT. On the right side of the commander’s seat footwell. Look outside the truck forward of the door and you’ll see a couple of louvers. INSIDE is a control plate to regulate fresh air.

I knew it was there, I’d just forgotten to close it off when the weather changed around November, shut it off last week when it was around 5F outside.

Big difference.

Found and closed the vent as you mentioned. Still blows cold air but not nearly as much.
Think I am going to give it a solid coolant flush once it's in the shop but for the cash I think a secondary / Mojave heater is in the
trucks near future...

 

[juanprado]

also make sure the cable going to the heater control valve does open it fully. My valve stuck around 3/4 but had more travel available but was not as smooth on the last part. I ended up changing the valve anyway as they are cheap and readily available.

I 2nd a good flush of the entire system and heater core. Nastiest crud tend to accumulate in these over time.

 

[Action]

I had to turn the valve in my '85 with pliers. Open in fall and close in spring. Lol.

 

[gcbennet]

The heaters in these things are very under engineered for sure. You'd think a vehicle that suffers from chronic overheating issues would produce nuclear heat, but it doesn't. I flushed my cooling system out really well and all sorts of junk came out. I pulled the heater core and rigged up a chunk of garden hose to blow hot water through it from my wash tub faucet, and another to discharge back into the sink. After lots of thunking and banging while forcing the hot water through all sorts of chunks of solidified sediment and crap came out. When the water pressure coming out is equal to what's going in, you'll know it's more-or-less cleaned out. Made somewhat of a difference in mine, which at the time was only giving luke-warm air at best. Now it's warm. lol