Ministry of Defender (MoD) AC / Heater install

[dkemm]

Every time I take on a new project on my LR Ninety....I tell myself that I am going to document it - pictures, timelapse, video....
So far, I have installed my Cummins R2.8, swapped LT77 FOR R380, Marsland Chassis swap, interior leatherwork, fusebox upgrade, etc.....
Well, at least this time I took (some) pictures to document the work.
I will preface this post - explaining that I am not a trained mechanic or fabricator...just passionate about learning and creating! I dont have a fancy shop or magical tools - the work is done in my carport - so I am limited by light, weather and space.

I live in the desert SW - New Mexico...typically we have what I would consider mild weather -- a few days a year over 100, some snow, a few days a year under 10degrees. For this reason, AC was not a must have item for my rover...the power windows were my form of AC. This summer we had a couple of weeks above 100 and I realized that I had enough "character building" in my life. I stumbled across MoD's offering and was intrigued by the fact that I didnt need to give up knee room inside my cab as the unit replaced the stock heater box. As it was - I had removed the heater box earlier in the year when I did the Chassis swap as I had already installed a webasto (knockoff) diesel heater for the cab space. In reviewing the MoD site, forums and watching their videos - I considered going the route of doing a full PUMA dash upgrade....but ultimately decided against that.

I placed my order and received my package in less than 2 weeks. I was pretty excited to open the box and see what I got myself into. The packing and organization of the MoD unit was great. I opted not to get a compressor from them to save on the shipping - and as I would need a bracket as well for my R2.8...I ordered those from Quick Draw Brand - arrrived in about a week. Now I had boxes of "stuff" and I had to come up with a game plan. Where to start, do I work in pieces so that I could still daily drive it, what needed to be done first..... as noted....I had previously installed a cummins R2.8 so I would be doing some customer fab work and positioning of items....

The Game Plan:
#1.
I decided to start by installing the Compressor and Compressor bracket on the R2.8. The new bracket had the power steering pump moving a little lower, so I did have to take into account the high/low pressure lines (braided SS lines). As I had a small leak from one of my fittings...I decided to simply create a new (slightly longer) hose with new fittings. Pump relocated, new lines in (no more leaking!!!) and new serpentine belt installed... a couple hours of work in the late afternoon.

#2.
Next up...redesign of my R2.8 cooling package. A little back story....as this will be somewhere in the v3.0 realm of R2.8 cooling.... The R2.8 dont like to be HOT....as they will throw codes and 'limp along'.
My v1.0 cooling was a single pass radiator - about factory size - a similar sized intercooler (cosworth RS500) and a 'standard' electric fan. This worked most of the time....
My v1.5 cooling was to add a bigger (more CFM) electric fan and reduce the size of the intercooler to provide clean air to the radiator - all this helped a little bit - but still got HOT
My v2.0 cooling was to add a 35% larger - Dual pass radiator (fills up the front space) and to move to a mechanical 17" fan - this solved all the H2O heat issues
My new v3.0 cooling - I had to accommodate the MoD condesor/fan and wanted to upgrade the intercooler - middle ground between the Huge and small to provide for better turbo air cooling. This required some cutting into the inner fender well (not too concerned as I was already far from stock...and not a NAS) to fit the FMIC pipes...but allowed for a more direct cool air exit / out of the radiator path (previous FMIC design).

 

[dkemm]

#3.
Install the MoD "Puma" AC-Heater box. This requires pulling out the old heater box / heater matrix (previously done) and cutting a hole into the passenger footwell. keep in mind that I have RHD - the kits are made for LHD or RHD and install the space of the old heater box - bolts and all.
#3a. Engine Bay housekeeping.... When I had removed the factory heater box, I had mounted my air compressor in the space....was nice while it lasted...became a portable air compressor again. I had installed my R2.8 Fuel Filter fairly close to the original heater box...but I had to move it forward to have space for the MoD unit - this required making a new bracket to shift my coolant expansion box and fuel filter forward about 2inches (clearance for the fuel lines). In test fitting the MoD unit - I also realized that I needed to move (remove) the R2.8 heater lines as well. These are hardlines attached with blue hoses...so relatively quick and easy.
#3b. With all items relocated to fit the MoD box....the next step was cutting the bulkhead/footwell (recirc air from inside the cabin) (sure hope my passenger never has moldy musty boots or stinky feet?). The provided instructions and template were easy to use, quickwork for a jigsaw. MoD provides a screen that goes between the cutout and the unit -- I augmented the screen with a "kick plate" that I 3d printed to keep an accidental toe from ripping the screen (fabric).
#4
Find a location for drier unit. As the pressure switch lives on the drier....I wanted it near the bulkhead for wiring ease and cleanliness. I ended up choosing the location of the original fuel filter. I actually had to modify the original bracket as I had failed to take into consideration the height of the pressure switch. That problem solved...aslo allowed for ease of running the hoses to the unit as well as to the condensor.
#5
Hoses - Hoses - Hoses..... I debated going to a local hydraulic shop to have hoses made....but as I like to do my own work...I purchased a hydraulic crimper and made my own hoses. I ended up being short about 2-1/2 to 3 feet of #6 hose that was included in the kit..... likely because it is geared towards a 200 / 300 TDI "universal" install...so I found some online and completed the connections. I already had a vacuum (used for my knife making / wood stabilizing) so all I need was an AC gauge manifold setup. Vacuumed the system....verified it held vacuum....and charged the system.

98% (no electrical yet) of the engine bay completed....now it was time to focus on the dreaded dash removal / internal work!!!!

 

[dkemm]

#6
Interior Dash:
Having previously removed the heater box from the engine compartment....I also removed the airway cover panel from the lower dash (the panel that has the ducts to the defroster) to gain more space for wiring the Raptor center console. I previously mentioned that I had upgraded my fuse panel...from the 1988 glass fuses to TDI panel which doubled the number of fuses I had available. To support the new fuses, I ran new 12v and switched 12v runs from the battery....the new fuses supported many of the switches in the new center dash - power windows, radio, power locks, alarm, aux lights, aux fuel pump (and fuel level), radio, and of course the new AC/Heater/Fan controls. As I didnt want to revert back to using the lower dash as a heater/ac manifold (and dust collector) - I knew that I would opt for 2.5" hose/ducts for the AC vents and 1.75" for defrost (thought it was a good idea to have defrost ability back again as was previously removed). (keep in mind that pictures may look backward as mine is RHD)
The square opening (1st pic below) is the bulkhead to lower kick panel opening - I needed to create a manifold that would then distribute air to the 2.5" / 1.75" ducts. (the hole that you see in the same picture is the opening to exits to the footwell - I had to remove the flaps/arm that is typically cable controlled for heat/defrost)
The last 2 pictures are the measurements of the driver side lower vent - I had to create a manifold that would connect this to the hose.

 

[dkemm]

#7. 3D Printing custom parts
I wanted to maximize the air distribution and velocity from the MoD unit to the new ducts. I decided to go with 2x 2.5" "Vent" ports and a single-shared 1.75 port for defrost capabilities. Drivers side and Passenger side vents would each have their own port from the manifold to make sure the air was equally split between the two - I created an internal baffle in the manifold. The single defrost port would support the 2 main defrost and an additional (custom) passenger door defrost vent.

 

[dkemm]

#7b. More custom parts:
Now I needed a defrost manifold to support the two main defrost vents and the new door vent, driver side lower dash interior hose connection, Driver side Tee to main vent and lower dash vent and lastly a custom lower dash (exterior) to a "Nostalgic AC" dash vent.

 

[dkemm]

#8 The final Home stretch!!!
ducts all run, vents tested for air flow, final location fitting - make sure all electrical is reconnected and grounded....time to put the dash together! I forgot to take a picture of the "almost completed dash"...but got the Raptor center console re-installed and tested all switches. Original plan was to have a small passenger glove box...but my octopus duct work had other ideas. Created dash panels with ABS, cut out vent mounts and heat molded to fit the openings on each side of the Raptor Center console. You may notice that I also created custom center console panels out of ABS to meet my switch / radio and gauge needs - the lower panel houses 12v sockets as well as USB / USB-C PD ports (both 12v switched and always on). The last photo showing everything tucked away behind the standard (non-AC) grill panel).

 

[Tbaumer]

3D printing is changing the possibilities. Nice write up & pics!

 

[MountainD]

glad you have AC! Loads of work getting there—nice job! How is it functioning?

 

[dkemm]

at first, AC was not as frigid as I would like...I will double check the pressures - I added the estimated amount of freon - but as my lengths of hose are longer than standard, I may need some more. I added more refrigerant to bring pressure up to where they should be (midrange) for the ambient temps - blowing colder as expected.
Heat is GREAT - the R2.8 heats up quickly and the blower works great. I can very likely remove my diesel heater that I previously installed between the front seats. The design of the MoD heater is great - a switch controlled electric valve that opens or shuts the flow of hot h2o through the unit.
My concern in designing the ducts was having enough flow (velocity) through the vents and location of the vents. Driver side was limited in options due to the binnacle, but I am happy with how it turned out. A little more work on the finish details of the dash panels is needed, but I can get to that later. I wanted to have a glove box space in the passenger dash - unfortunately my ducts consumed more space to be able to create a space.