Webasto fault 07

[tombpurring]

I have a webasto at2000 diesel heater with a simple temp control switch. The fuel is connected to the main fuel tank. Dont know where pump is.
I replaced the glow plug and gauze.

Turning on, i get an error 07 which is meter pump interrupt.
System was all working 12 months ago. I bled the fuel line. Ive shut down the 12v system whilst starting up.
I can only think of wiring issue. Does anyone know which wires are used for pump. I cannot follow the wiring diagram. Ive pulled apart and reassembled a few times, do i could have unconnected a wire.
Online company had sent me the wrong glow plug originally
There is an 2 point orphan plug near the heater but this has always been there. I think that was for a more sophisticated controller( cut out etc)

 

[Ostara24]

Do you hear the pump clicking on start up?

 

[tombpurring]

Do you hear the pump clicking on start up?

Cannot hear any clicking
It is on a motorhome. Will have to find pump and see where wiring is going to check it plus any fuses. There was major work done on engine, so maybe they stuffed the wiring in there.

 

[tombpurring]

Ive found the pump. Disconnected wiring and put voltmeter on it. No current when starting up heater. Back to wiring. Where should i look. See photo.there is an orphan connection. There is 1.25 volts and 10amps coming out of this on startup. I think this was here beforehand. I'm an electrical novice

 

[PaulRainbow]

This will be a wiring issue, there is no fuse in the pump circuit.

 

[tombpurring]

Does the wiring from the pump go to the switch or to the heater?

 

[Ian_Edwards]

I don't know that particular model of webasco. But there's a general operation sequence when a diesel heater starts up is:
1) The fan in the heater comes on and blows air through the heater, to clear any vapor which might go bang.
2) The glow plug will heat up, and you'll expect to see a significant increase in current drawn.
3) The metering pump will startup, it doesn't take constant voltage, but is pulsed by the controller in the heater. You should be able to hear it tick, but not immediately, it takes a minute or two for the heater to go through stages 1 and 2. Your multimeter may not be able to see or measure the pulses.
4) The heater will then fire-up, with luck.
5) if it fires, the glow plug will turn off, and the heater will run. If it doesn't the heater will go through a shut down sequence, pump off, then glow plug off, then the fan will run for while to clear the combustion chamber.

If you understand the sequence, it's much easier to fault find