g741.org

getting ready to paint the rig,and up-grade the heater to this... http://www.summitracing.com/parts/SUM-9 ... mage=large 28,000 btu's! Fits under the glove box just fine,with plenty of foot room.

Looks like a nice heater. Is it 12 or 24VDC, I didn't see it in the ad?
Speaking of heaters, I have a similar style of unit that came with my truck. It is called a "Mobil products model 556 heater"Division of Hup Inc. I have not hooked the motor up since I am not sure what voltage it is. My truck had a cobbled collection of 12 and 24 volt accessories on it when I got it. I can find no record of a Mobil Products that made cab heaters to find out? It seemed to run really fast on 24, but maybe it is meant to have a rheostat?

I installed an M151 type hot water heater in my truck last season. I did so just at the end of winter, and got to try it out on one or two chilly days. I want to give it a workout on a real cold day this year to see how it performs. With the rag top, I doubt this little unit will make it toasty inside. But, as long as it takes the chill off, that's good enough for me.,

That heater in the link above is 12 volt. Testing air flow on the bench was awesome. Pretty damb quiet too. I think Its going to be a good one. I use to have a small "southwind" products that was the size of one of those small square tissue boxes. Now that one sucked!It was also loud like a freight train.

HI, WHERE DO U PICK UP 12V? IF YOU HAVE A TOTAL 24V SYSTEM.
OR WILL THE 12V MOTOR RUN ON 24, BUT 2X FASTER? ALSO WHERE DO YOU GET AND RETURN THE ENGINE WATER? THANKS BOB

Bob,
One of the water connections is on the passenger side rear of the engine head. It should be marked "HEATER" It will probably be a standard pipe plug. The front connection is usually made through another pipe plug in the steel elbow in the radiator hose. On Power Wagons it isa also done at the thermostat housing but I dont think the M37s do it that way.
And yes, a 12 voly motor will spin right along on 24 volts, just cant say for how long. I ran a 6 volt heater on 12 vots for years with no ill effects, but I dont know how 12 volt motors do on 24.
Tim

powerwagontim wrote: ...yes, a 12 voly motor will spin right along on 24 volts, just cant say for how long.

It will run at about twice the intended speed, but it will burn out sooner or later. Of course, it will burn out eventually on 12 volts, too. If you're worried about it, you can always put a resistor in line to drop the voltage to the motor. Anyway, however you do it, it's nice to have heat in the winter!

My truck had connections for the water lines on the cylinder head, on the radiator hose, and another at the water pump. However the plug at the water pump was 1/2 in pipe thread. The others were 3/8ths. Just make sure you have an 8 point socket so you can take those square plugs off.

THANKS GUYS FOR ALL THE INFO ON THE HEATER 12V/24V HOOK UP AND THE WATER CONNECTIONS. SO IF I UNDERSTAND IT CORRECTLY I NEED THE FEED BEFORE THE THERMOSTAT AND THE RETURN AFTER THE THERMOSTAT?? THE PLUG IN THE HEAD IS THE FEED AND THE PLUG IN THE RADIATOR HOSE IS THE RETURN??
BOB

If your truck is 24 volt, I have had great success with a Maradyne heater sold at Boyce equipment. They also have 12 volt ones.