M818 Benmar Arctic Heater Installation

[JasonS]

The standard coolant heater, even when installed in the cab, really isn't quite enough so I looked at the arctic heater options.


Based on the discussion on this forum, the Benmar seems to have a better track record. As it turns out, there is a 20k btu Benmar heater available from the usual auction house. It is really quite small and opens up options regarding placement.

 

[JasonS]

The heater is mounted on the rear trans tunnel.


The exhaust is routed out the rear. I fabricated a secure means of supporting the exhaust and routed it out behind the cab, next to the transfer case, and rear of the fuel tank.

 

[JasonS]

I installed a pickup in the tank, routed line to a pump mounted on the fuel tank support, then push lock hose to the inside of the cab.

 

[JasonS]

A better pic showing the general location. Yes, the outlet will be very hot. I plan on rolling a shroud to prevent inadvertent contact. The fuel filter is the one used on the multifuel flame heater.

I tested this heater quite a few times before committing to the install. Once the air is out of the fuel line, they will reliably start within 2 minutes. The 5-pin connectors are available on Amazon for ~$25 each if you need to make your own cables. I will finish out the electrical once I decide where to mount the control box...

 

[JasonS]

The success with the Benmar cabin heater led to the installation of a coolant heater.... Benmar also made a 15k btu coolant heater; it didn't put out as much heat as my Stewart Warner 939J24 but the small size and built in pump made it very appealing. I first planned on installing it in the driver's side toolbox but there is a spot on the fender which looked ideal.


Since this part of the fender is a little difficult to get at, I started by making a drill template out of aluminum. I clamped the template to the fender, drilled the heater mounting holes, and scribed the exhaust and drain holes. Using a compass, I put the point into the scribed circle and drew three arcs to find the center.


The heater flexed the fender a little more than I wanted so I fabricated a strut to tie into the air filter housing. I am a complete novice when it comes to TIG but I believe it works better for small parts than a MIG.

I still need to finish the plumbing and electrical but I mocked up a potential exhaust to show hot it could work.

 

[BKubu]

Looks very cool. I've had fuel burning heaters in trucks. They work great. What are you doing for defrost (or did I miss that)?

 

[canadacountry]

never seen many fuel heaters but have always liked them in general tho, seriously plan on one for my upcoming truck (whether the heater unit is an ex-military used one or a new/used commercial truck one is up for eventual debate but mm) as well

nothing like just a little bit of power draw and "unlimited fuel" to literally un-freeze the cabin with a little bit of friendly 'haste' on an early morning -19c winter with some wind blowing .. and the sun isn't quite up yet (you wonder why i don't always like some car rides well before 8am but umm mm yeah say no more)

 

[JasonS]

Looks very cool. I've had fuel burning heaters in trucks. They work great. What are you doing for defrost (or did I miss that)?

I still have the regular heater under the dash that can be used for defrost.

 

[ODAddict]

Nice account of your professional installation. Thank you.

Where did you get the metal exhaust line? Or was it part of the kit?

 

[JasonS]

Nice account of your professional installation. Thank you.

Where did you get the metal exhaust line? Or was it part of the kit?

Another auction purchase. Really good value IMHO.

 

[JasonS]

Finally got the wiring and coolant plumbing complete. I made one new power/ control cable using connectors from Amazon. This cable is routed next to the transmission tunnel hump. Since both heaters use the same fuel pump, I used a pair of diodes let either heater controller power the fuel pump.

 

[Superthermal]

I think my cab would be much warmer if I had one of these boot seals rather than an old shirt stuffed into the gap of my shifter coming through the tunnel. For real... LOL. I haven't seen this design with the rubber waves being vertical rather than horizontal. Where did you find it if you don't mind me asking.

 

[JasonS]

This is a "Rubber Shifter Boot For Freightliner FLD and Classic models 027076457 284053401" Should be able to find one buy it now for ~$20. I got the trim ring from a separate online truck retailer; can't remember where though. I looked awhile to find one that wasn't insanely priced. I mounted the boot with nutserts to make it easy to remove/ install.