Water pump tensioner woes :-(

[306DD]

Hi All,
Is it possible to test a water pump tensioner unit on a 156THP engine? Roller and bearings are fine, it's the electric end that's the problem. Mine seems to be engaging even from cold - which I'm pretty sure shouldn't be happening,

 

[Pedro]

The water pump works on a clutch system meaning the ECU detects the water temp rising then engages the pump to pressurize the cooling system it will only work off the engine temp getting warmer never vice versa you may have a temp sensor fault or a software problem ?

 

[306DD]

Cheers, seems to be engaged all the time. Just wondered if there was a way to check actuation before buying a new unit!
Suppose it's better this way than not engaging at all.