Heater location

[chicklin]

So, I picked up one of those M151 heaters from Army Surplus Warehouse. It looks like I'm going to have to make up some brackets to get it mounted. But, before I do, is there any problem with mounting this thing in the engine compartment instead of under the dash?

There's plenty of room on either side, but it would probably be easier work on the engine side and it would save a little leg room. Is it going to be less efficient if the core is not inside the "warm" cab?

[randyscycle]

Actually that was the idea I was thinking of too. Keeps the under dash area clean and free of extra equipment.

My plan was a deuce style heater where the fan and heater core were under the hood in the spot where the battery would reside in a civvy truck, then a duct inside to a distribution box for heat and defrost.

The factory hot water heater in my deuce works just fine in that arrangement and will run you out of the cab in any cold weather we've had here, as well as keeping the windshields defogged just fine.

[Beltfed Only]

What are you going to use for a speed control for the heater fan?

[chicklin]

What are you going to use for a speed control for the heater fan?

Just one speed, on or off. I don't need anything fancy, just something to blow heat into the cab.

The original M151 setup used a resistor, a 3-way switch (hi, lo, off) and some sort of Y-cable. There's some info here:

http://www.garbee.net/~cabell/heaterinstallation.htm

[Snuffy]

I have a military 3-way (Low-off-High) 2 wire for my heater. They said it was a 3-way...we'll see.

[chicklin]

I foung a resistor switch with 3 posistions at napa. low med. & hi. just 2 wire hookup.

Ah, good idea. I'll check that out.

[amphi]

I foung a resistor switch with 3 posistions at napa. low med. & hi. just 2 wire hookup.

Can you post the Napa part number for this? Does it have a resistor built in?

Most blower motor resistors are mounted in the ductwork with air moving over them for cooling.

This five-ohm resistor would work perfectly in free air for two speeds at 24v:

http://cgi.ebay.com/Power-Resistor-A...QQcmdZViewItem

As I previously posted, this will also work for running a 12v blower on 24v.