Td4 air con problem

Hi, my 2001 my has a problem where the air con has no earth at the fusebox relay when the car is running, having checked another Freelander, it should have
Has anyone else had the same problem ? Everything works ... Ie gas is fine, on off switch is fine, compressor works but as I said when the car is running there's no earth
Anyone got any ideas ?
Thanks in advance .... Rob

Which engine?

Depends which relay and which connection you mean. On the TD4 there is an Air Con relay which has a feed via a contact to the clutch (which is then earthed) and so the clutch is presenting an earth at terminal 87.

For the relay to operate it has a feed and gets the return (earth) from the engine control module which is on relay terminal 85.

Bit more info to take this one further !

But if no earth on terminal 87 suggests clutch winding is open circuit or a wire to it or a connection.

Cheers.