Warning light problem on 406

Can anyone help with a problem I have on my 2000 406 Rapier? Whenever I
switch on my air conditioning a warning light comes on that tells me the
engine temp is too hot. This happens even when the engine is cold. I have
changed the sender unit located in the thermostat housing but no luck. I
would appreciate any help with this problem.
Thanks - Steve

 

Check the relays next to the fan units behind the front grill, under a
long plastic cover. Also adjacent to these are the resistors. Remove
these (one screw) and check the connections for corrosion and the
windings for breaks (common). Note they are colour coded, grey and
black. Any corrosion found try and clean up, but may need to renew the
component. Also check the plugs to the components for burning and/or
corrosion. Clean up as necessary or if really bad the loom is
available and easyish to change.

 

Thanks Nigel as soon as it stops raining I'll give it a try
Cheers Steve

 

Try the connectors round the Bitron sensor if you have one. My Citroen does
similar things intermittently which seem to be cured by fiddling with the
connectors