axiliary water pump staying on

[morganite]

Hi, 1.6 td, my axiliary water pump is staying on and running the battery down, is there a relay somewhere that should shut the water pump down once the coolant has cooled down? or is there something else controlling the pump? any advice appreciated

[ZsZ]

There should be a temperature switch in one of the coolant flanges. Wire is brown with red tracer.
Late system with plastic flanges have two wires going to the switch, the other is brown.

The temp switch switches the ground, while the motor has unfused 12V.

Either your switch is bad or the wire grounds somewhere.

[ZsZ]

Early switch:

https://brickwerks.co.uk/product/coolan ... ump-early/


Late switch:
https://brickwerks.co.uk/product/coolan ... pump-late/

[Oren Kipnis]

Or a faulty relay in the electrical cabinet in the engine bay.

It is marked "J151" (if still original), and is the middle or the RH relay in the cabinet.