The one I remember just ticked at about once a second.

They are quite well known for failing.

The tick rate is probably controlled from the heater unit. See if there is
power from the heater unit or possibly pulses of 12v.

Alec


"Mike" wrote in message
...
Installing a Eberspacher D2 air heater but no action from the pump. Can
any one confirm if I stick 12 volts across the pump connector it should
turn, or does it need a signal from the heater unit?