Eberspacher D2 testing

[icarusbop]

Hello:

I have an Eberspacher D2 heater onboard my yachy whcih has stopped working over the winter.

I have done some testing and suspect the problem pay be with the fuel pump.
Inn the past I can hear the fuel pump 'clicking' as it pulses the fuel through, this is no longet happening.
I removed the wires from the pump and measured the voltage - it is only reading 9v, I know it's a 12v system, so assume the voltage drop is due to dodgy wiring.

Fir extra tresting, if I connect the unit directly to a good 12V feed, should it pulse on it's own, ir does the controller pule it with a signal? As an extra question - the case on the pump is really grubby and both my wires are black - can anyone advsie if the unit requres the volatege to be connected the right way around or does it not matter.
(preumably, if the pulse signal comes from the controller, the polaritiy of the power would not matter, working on a theory that the pump in only a solenoid unit)
One last thing - if the pulse is driven by the controller and I am getting a steady voltage (albeit 9v not 12v) would this indicate a potential controller failure?

Thanks
Ian (Tacks)

 

[David2452]

Never, ever connect the pump direct to a 12v source, just pulse it or it could burn out, it is difficult to get an accurate reading with a meter as they will not respond quickly enough to the pulses generated by the ECU. The pumps are not polarity dependent. Your last point indicates a potential ECU issue as there should not be a constant voltage of any level at the dosing pump, pulse testing the pump will confirm that.

 

[Alpha22]

If you connect a 12v bulb in place of the pump, it should blink, probably less than 1 per sec on when in the initial fuel stage. If it just glows then you have a problem.