M151A1 Heater Installation

[ohiomgman]

Some years ago I purchased several of the boxed up US contract "heater kits" for the M151 series of 1/4 ton truck. I am at the point now where I would like to install one of these kits in my Mutt. I have unpacked the kit. There seems to be no..."take me by the hand and show me how to install it instructions" boxed up with it.. Where would I find THOSE? If they even exist? I can prob diddle around and figure it out...but... I would like to have my install..."look" like it was "Depot installed."

Just tired of not having a "hot air machine" installed and having the "fix"sitting on the shelf...looking back at me.


I also have the Standard Military, aluminum hardtop and doors...mine came with them. Took them off as soon as I got the truck as I had an M-4 pedestal for my M-60 MG to install...

I have no plans to drive my unibodytoy out in the salt snow and crap...but it would be nice to have defrosters and heat on some cold dry days....

[whirook]

Check the TM9-2320-218-34-1 manual.
http://www.g838.org/g838_manuals/TM%209 ... ug1982.pdf
The heater instructions start on page 732.

[Ralph Fuller]

Here is another source...same manual
http://www.scottie4442.net/mv/mutt/docu ... 8-34-1.pdf

Page 682 is installation of the "Brush Guard Cover". You can install this last without any problems.

Page 684 is installation of the "Slave Receptacle". IMPORTANT NOTE: INSTALL THIS FIRST. Once the heater is installed, you will not be able to install this without first removing the heater.

If you have a "passenger grab handle" on the dash in front of the passenger, ensure the nuts are tight with lock washers. You will not have access here once the heater is installed. NOTE: you can spot weld the nuts on the back side of the handle, and this will allow you to remove the handle in the future. (You won't find this in any manual....just a neat trick).

To install the heater, print pages 734 to 764.

Do not remove any parts from the little numbered packages (IE: screws, nuts, bolts, etc.)
Place all of these on a table that you won't be using for a week or so.
The instructions are very specific as to where you will have to measure from different points to ensure the holes are drilled correctly.




I installed the heater by myself, and used a jack to hold it in place while I bolted it up.

[BG6]

If your MUTT doesn't have the aux power "jumper jack" installed, and the kit didn't come with one, BUY ONE NOW and install it BEFORE you put in the heater. Everyone I've ever talked to who tried to install the jack after the heater was installed seems to be willing to commit suicide rather than ever try that job again.

[ohiomgman]

My kit came with the jumper plug and the canvass weatherfront for the grill. I will install the plug first.

[ohiomgman]

NOW...I am doing the install of the heater. A Bubba had installed a milspec heater kit (kinda) before I purchased the truck..I am just taking the whole mess out and installing EVERYTHING new right out of the box..What a PITA. I do not think one of the the previous owners had a tape measure or any idea what he was doing.

[rickf]

ONE other thing you need that has not been mentioned, your favorite pain killer of choice in large quantities!


Rick

[Fil Bonica]

The installation of a heater kit in a 151 is with out a doubt the most challenging project associated with that vehicle.
Have done it twice and hopefully will never have to do it again.
Women and small children should be away from the area while you are working. Otherwise they may hear words never spoken before by man.
Take it slowly , RTFM and you will succeed!

Fil Bonica

[rickf]

OH, I forgot to mention, Take the pain killers before starting the job!!! This job rates right up there with replacing the master cylinder. I know all of you young guys are saying "what is he talking about? it's not that bad" . You too will get old!


Rick

[199th mp]

i did this on my jeep and considered taking up heavy drinking before i was halfway through--mind you, i'm 61 years old and have never tasted beer or liquor. this is not a happy time waiting for you. you will say bad words and think evil thoughts as you stare at the axe on the side of your jeep. you will have aches old people should not have, even if you aren't really old yet. also, the wiring diagram in the book did not match the wires and switch that was in my kit. have fun!!!

[ohiomgman]

OH, I forgot to mention, Take the pain killers before starting the job!!! This job rates right up there with replacing the master cylinder. I know all of you young guys are saying "what is he talking about? it's not that bad" . You too will get old!


Rick

I replaced the MC a couple of months ago. DAMN! More fun than a barrel of vipers. I am 61 years old and a fatass....Used to be I could do in a day what now takes a week. Sucks to hit the age wall....

I cheated...I completely assembled the heater assembly to include all of the water hoses and duct pipes and simply using the Jeeps scissor jack...to hold it up...I fed the heater's water hoses and duct hoses in the right direction pulled the slack out of them (in the engine compartment) while raising and wiggling the assemble...and pretty much had it installed in about 20 minutes. Hard part was laying out for all them damn holes....Some idiot that had the mutt before me, made the hole where the "fresh air door" is, waaaaaay to big. I had to make a piece of 18ga steel fit the existing hole ...mig it in...then cut the new hole out..in it. I really dislike un-bubba-ing, stuff.

NOW......Tomorrow, I will finish it up, by installing the ductwork, wiring and switches, etc., on the drivers side. It helps to have a scissors lift to put it all (yhe mutt) at an easier, to work on height....

Yep...installing a heater... properly...is a PITA. It will be worth it though when Jack Frost is nipping at my tailpipe.

I helped a buddy custom modify one of the same kinds of heater kits into fitting his totally restored M-37. He didn't want that clunky hot water heater mounted on the Left front fender. The install we worked out looks like it grew there. Even used the little "fresh air" door to bring in fresh air.


I wonder what I should do with the the heater assy i took out of my Mutt...? Prob keep it for spare parts. Naaaaw...toss trhat crap out.

[ohiomgman]

Just wrapping the heater install up now...I really had to deplete my packard connector stash to make up all of those jumper wires for all the circuitry. Time to stock back up. Who has the best stock of the connectors?

[Rainman]

Hey mgman,
I'm going to need some myself, so keep me in mind when placing that order please.
My project needs the headlight wiring un-bubba'd
Rainman

[ohiomgman]

The left side heater/duct defroster hose, where the hose comes down from the left side defroster is impossible to bend to install correctly. I struggled with trying to get it to bend almost 90%.... and trying to get the junction box that clamps to the steering column back up in. That 40 year old hose was just not going to bend. I gave up on it. I just ordered some plastic, over a steel spring, air duct/hose. It is VERY flexible hose indeed. I ordered from McMaster-Carr. My back hurts. My hands hurt. When the hose comes in I will cut a piece off and finish up the drivers side in about a half of an hour. I was thinking about the poor Army mechanics that had to put them heaters in while it was in the motor pool. Poor guys.

I wonder if those heater duct hoses were that stiff when they were new? I have other work to do and can only work on my mutt for a couple hours a week. The passenger side went right together...

NOTE* When I first got my mutt...I noticed that there was not much in the way of air moving up to the drivers side defroster...plenty on the passenger side...

I found no hose at all except a piece of black rubber 90% pipe that was "pointing" at the duct that screws on under the dashbord. I have run my new heater and it seems to GUSH heat out. I think the old one was improperly installed and the core was plugged with "stop leak." I notice that stop leak nearly always plugs the heater core up.

Now I am waiting on some flexible ducting to arrive and it will be a quick finish.

[199th mp]

just a question for all of you that have heaters of the hot water type, not the gas fired type. even though my engine temp runs where it should, the heater does not produce a great deal of heat, and even though i have verified the defroster and other hoses are firmly attached, i don't get much air flow through the defroster. are these two conditions common/typical? the blower sounds like a freight train on high but the output is not impressive.