Defender 300tdi Air con not working

[milkshakes]

Hi all,

Recently purchased a 300tdi defender hardtop (will post on deefers when she gets a proper clean) and the air conditioning has stopped working. When i bought the truck and for the next few days it worked very well and was cold... But now it seems as if the air con clutch isn't engaging although the fan still works fine. The only thing i've checked so far are the fuses (i assume the air con fuse is with the rest infront of the gear lever) and they were all fine.

Thoughts?

[jboot51]

300 TDI aircon fuses are in the the battery box.
2 x fuses
2x relays
There is a little black box in there with about 9 wires connected to it, this is the control module.

[lro11]

I have had two issues with 300 tdi air con over the years first one was the compressor clutch did not engage because the system was low on gas due to a leak on the aluminium pipe on the firewall. The second was the black control box under the passenger seat. Dwayne at MR told me that this is a common problem and the module supply is drying up. He still has a couple in stock but if you are handy with a soldering iron I would have a go at repairing it as it might be just a dry joint.

[Bushie]

Even when it is fixed "working" is a relative term.

Martyn

[86mud]

My 98 Defender air con fuses and relays are with the other fuses the main fuses on the firewall

[87County]

There is a little black box in there with about 9 wires connected to it, this is the control module.

This " little black box " and is a thermo amp, OME replacement no longer available but generic item can be substituted

[ian_gregg]

I fixed mine once by just wriggling all the connections in the battery box. With the ignition/engine off, pull out the plug (from memory), spray with WD or similar and put it back.

[steane]

The best thing to do with a 300TDi Deefer a/c system is turn it into an onboard air system and liberate the passenger side footwell. :D

[jimr1]

Hi , I put a test light at the compressor end to see if you have power , that's with It switch ,on of course , or get someone to switch you aircon on you can hear the clutch kick in .

[Craigb]

you can see if the pulley turns even, ie, when clutch not working the centre part sits still and then turns with the clutch in.

But the main point was to say that my 96 110 300tdi has the fuses and relay attached under the normal fuses on the firewall, but it is an aftermarket 'iceberg' fitted in 2000, although it looks a lot like the original. So if fitted later, even if an original one from a wrecker, then the fuses might be wherever the fitter chose.