Thread: 300tdi airconditioner not working

Hey Chris,

I've just been through this with my 1994 Def 110 and found the wiring diagram posted in this thread very useful for problem solving:

Air con wiring advice needed?

That's the same link posted by Isuzu110 above, but I wanted to make it more obvious.

Firstly, check the relay on the far right (under passenger seat as you look from passenger door). The white wire should show 12v when ignition is on, and the red wire the same (this would confirm that relay/fuse is ok). This red wire supplies power to the blower switch and most of the system from there.
Next check the red wire going into the Thermo-amp (the box on the left) under the passenger seat, which should be showing 12v with ignition and blower switch on.
Hope I'm not teaching you to suck egg's, but I'm sure you get the idea.....

The problem I had was the Thermo-amp itself, which was not activating the pressure switch, and therefore the clutch. However, in my case the blower was working, but I had lost pressure in the system due to a clamp rubbing through one of the ac rigid pipes (drivers side corner near the firewall). After repairing the pipe and getting it re-gassed, I have made a temporary fix of bridging the thermo-amp red wire to the black wire going to the pressure switch (effectively by-passing the thermo-amp, thermo switch, & probe). I do plan on replacing the Thermo-amp with a 3rd party variable thermostat, but for now I just have to be careful it doesn't ice up as the compressor is always pumping when the blower is on! ......the things I'll do the keep the misses happy! ........

Presto that was really handy (eventually) - in typical LR fashion another issue popped up before i had a chance to have a good look at the AC, the vacuum pump died then the booster then the new vacuum pump. Anyway thats sorted now.
I went through Prestos steps, turns out theres no power getting to the relay from the ignition (the white wire). I jumped some power across from the battery and the fan and compressor both work (and cold with engine running)

Is there an easy way to trace the ignition wire - as it doesnt appear to go through the main fusebox (or does it??) not a white wire that i can see.
I could just run another wire from another ignition source BUT id rather sort the issue properly. Any help would be much appreciated.

Thanks
Ringky

I'm glad my waffle helped someone!
Unfortunately my defender isn't with me at the moment to check the white wire route, but as I didn't have any issue with the ignition pick up, I never really looked at that, and don't think it will be easy to follow/trace anyway. I'd suggest it must go through the main fuse box!?
Will try and check later in the week.

An update on my system....

I pretty much hit the icing problem on the first day out, so solved the issues using one of these, which I purchased from Ashdown Ingram.

Product » PT. Indotek Perkasa Jaya

This is a very simple mechanical variable thermostat, which I used along with a relay, to bypass the Thermo amp, thermo switch, and probe in the standard installation.
Referring to the diagram I posted above, I used the two yellow wires from the old thermo switch (at the blower switch /dash end) and mounted the TSX1012 next to the blower switch with the probe extended into the air flow. Then in the battery box I connected a relay fed from the Red return wire from the blower switch, activated by the TSX1012 (one of the yellow wires). The output from the relay connected to the black wire (pressure switch and clutch).
Since I completed this mod, the aircon has been working very well

Total cost for the fix (TSX1012 + Relay) was about $35.

Hope this helps someone!

I really need to fix mine....I have put up with it for too long!

Mine freezes up after about 40 minutes of run time. First sign is ice spitting out of the vents, then the air flow just starts to slow down even though the fan is not changed rpm. I turn it off and after about 30 minutes, it is right to go...that is after about 4 litres of water pours from the drain pipe.

I assume this is what you faced Grant?

Thanks