heater booster system

[van man]

Hello i have just bought a mercedes sprinter van 308 cdi mwb
i am having trouble with the heater booster system.. When you press the button the light comes on, but nothing happens it does not start up......... I have taken out the unit, and checked the motor by connecting it to a battery that seemed fine, and have disconnected the diesel soleniod which is near the fuel tank, and have tested that on a battery and that clicks, but still it will not go....

Can anyone help me please
mark:?

 

[television]

I am not good on sprinters, but are you referring to the engine heater and not the interior heater

 

[Cnics]

The heater booster is the same as on all the CDI engines if i remember correctly. Mine doesn't work either and hasn't for some time. I've had larger issues to deal with though.

Look at the variables.

It needs fuel, water, and power. If it has all 3 then it needs the conditions.

Conditions are that there is enough battery voltage, there is ENOUGH fuel (it won't work below a certain amount of fuel) and that the external temperature is at or below 5degrees. So, there has to be something that tells it all these 3 things.