Im experiencing a parasitic battery drain issue with my 2002 vito 112 (638)
Narrowed it down to fuse 12 (heater control unit circuit)
I have a parasitic drain of nearly 1A.
When the car is turned off there is still power to the solenoid valve that controls the heating (under bonnet behind the airbox)
The solenoid is operating correctly when the car is running. But the only way you can de-energise it is by pulling the fuse/ cycling the power.
Im at the point of installing a toggle switch into the circuit for a quick fix.
Im guessing there may be a something latching electronically inside the heater control unit in the centre console.
It does control heat on/off ok, i can see the voltage going from 0V heat to 12V cool (bypass)
There doesnt seem to be any relays inside the control unit though, it looks more like a potentiometer. so i cant work why it continues to send voltage to the solenoid after the car is turned off.
Am i missing something here?
Im about to source another heater control unit anyway and see if it fixes the problem. But i feel its not going to.
Any help would be greatly appreciated,
Cheers.
Narrowed it down to fuse 12 (heater control unit circuit)
I have a parasitic drain of nearly 1A.
When the car is turned off there is still power to the solenoid valve that controls the heating (under bonnet behind the airbox)
The solenoid is operating correctly when the car is running. But the only way you can de-energise it is by pulling the fuse/ cycling the power.
Im at the point of installing a toggle switch into the circuit for a quick fix.
Im guessing there may be a something latching electronically inside the heater control unit in the centre console.
It does control heat on/off ok, i can see the voltage going from 0V heat to 12V cool (bypass)
There doesnt seem to be any relays inside the control unit though, it looks more like a potentiometer. so i cant work why it continues to send voltage to the solenoid after the car is turned off.
Am i missing something here?
Im about to source another heater control unit anyway and see if it fixes the problem. But i feel its not going to.
Any help would be greatly appreciated,
Cheers.
