Air Conditioning Installation 1550 Unimog
Inside The Cab
The first thing to do in the cab is to take out the glove box. The installation kit is designed such that you
can replace the glove box in it original spot and it is fully functional. There are five screws (phillips) in the
glove box to remove and it comes right out. Do not mess with the screws for the door it comes out as a unit.
You have to remove the screws to the instrument panel (4) large phillips. The center vent has to be removed from it
mountings in order to get to the two phillip screws that hold the bottom of that panel in. The vent next to the passenger
door has to be removed (2 phillips). This will give you good access to the top the knee pad.
There are four plastic rivets holding in the bottom of the knee pad panel. You can see two of them when
you remove the glove box. If you gently pry out the round disc you can then remove the serrated part and
they can probably be reused. If you brake them that may not be too bad since I don't see where they need
to be reused.
Here is where things started to get real complicated. My truck has some sort of prototype computerized
4x4 and locker traction system. Sort of like the new SUV's. If the system is turned on and it senses wheel spin it
will put it in 4 wheel drive. It will also engages a front or rear locker as needed. It is sort of neat but I never used
it. It have a manuel over ride so if I what 4 wheel drive I just flip a switch and it is engaged. Same with the
lockers. These are all electrical-pneumaticly controlled. You can watch the drive train picture on the dash
that shows when thing are engaged and disengaged. Off road the lights just keep blinking on and off.
Took out all of the computer stuff. I had to trace the wires to the instrument panel and remove as much
of the set up as I could. The wires to engage the 4x4 and lockers were traced out and they we put on
switches on the instrument panel. Needless to say that was fairly time consuming project. You can see where the
heater tube on the left side was removed. If you leave it in I think you may have a hard time getting the unit
in. When I put it back it would not fit and I had to shorten it. I think that the insulation around the engine
cover made it a tight fit. The air duct on the top can be left in place it did not get into the way.
The hole is the firewall was drilled. The instruction said for a rectangular hole but I had a hole saw kit
and thought it would be easier. I might try to follow the instruction next time. The hole above had a
rubber stopper in it I don't know what is was for. Now is a good time to put in some sound proofing.
You will never get a better view. I used some half inch open cell rubber glued in place. Hopefully it
will help.
Installed unit. Make sure that the knee pad is fully engaged along the whole length before screwing it is.
I had to lengthen the wires to the thermostat since I wanted it on the instrument panel and not on the
top of the dash. I also had to lengthen the wires to the fan for the condenser since it was mounted back
on the chassis. Note the heater tube to the floor I had to cut off the end to make it fit.
The unit sits in there pretty nice. I left out the glove box until I have it working just in case. One thing I did not
do was to drill the hole in the floor for the drain. That was not a good idea since now it is real hard to get a
drill in there. So drill all holes before putting in the unit. The supplies plastic tubing is a little short. It will get
the water out of the cab but will run on some mog parts before it gets to the ground. I got a longer piece so
I could get it past all the metal parts before hit the ground.
The switch that comes with the unit is the newer model. It fits right in the newer SBU dashes but since I had
an older model (1992) I make a small piece of aluminum to fit the switch and them mounted the switch. I already
had a hole in the spot where I took out the traction control switch. The round switch below is for the thermostat.
The instruction show it mounted on the top of the center of the dash but I liked it better on the panel. You have
to lengthen the wire to it. The three switches left of the air switch now are the four wheel drive, rear locker and
front locker.