Right............ rushed home today with the intention of pulling the heater and swapping it with the spare unit.
But before doing that I did wonder about carrying out the test as in the trouble shooting manual from Robins site, OK so its not the exact same heater as Robin explains but its dam close
http://www.rmsconsult.co.uk/berlingo/fi ... g_Tree.pdf
Anyhow it says to connect a 12v bulb to the connector of the dosing pump and it should start to flash after 30 secs, so as one last try I thought I would just see what would happen, to be honest I didnt expect anything.
So I found a 12v 3W bulb which I felt was reasonable, but rather than struggle under the van I pulled the connector off the heater ( leaving the main supply connected ) and connected the light to the pin were the blue wire would have connected (pin 6 from memory but dont take that as 100% but it is the blue wire pin on the heater ) and then I fed the heater a 12v+ direct from the battery to pin 1 or where the black wire goes onto, think its pin 1 .
Anyhow as I thought the heater fans fired up, when low and behold after 30 secs the bulb started to flash !!!!!! so whats going on ??
Right so with that I disconnected the make shift light assembley and connected the heater back up how it should be and pulled the fuel line off the heater and fired it back up again.
This time after 30 secs a steady if very small flow of petrol came out of the pipe
![Cool 8)](./images/smilies/icon_cool.gif)
so with that I stuffed the pipe back on the heater and waited...........thinking well its got fuel the fans are running its now down to the internals to do their stuff and within about 20 secs I heard the muffled roar of the exhaust as they do when they fire.
OK it was a bit hit and miss to start with and appeared to go out several times over the next five mins but it re-lite itself and started to settle down to what sound like an even burn.
The water started to warm up nicely and everything "seems" fine !!!
Well I thought it needs to be shut down and re-start a couple of times before I'll be really happy so I switched her off and allowed it to run down as they do, then restarted her...........this time she was much happier and lit within about 2 secs of the pump starting which is how it should be, also the burn seemed much more stable, so I left her running for about 10 mins and then checked the over heat part by turning off the vans interior heater fan and allowing the temp to increase to the cut off which is did and at about 80C ( measured on the outside of a pipe) the heater went into over temp and shut the burner down , I turned on the vans heater van to number 1 and waited for the temp to fall and low and behold the heater re-lit again
So it all looks to be fine now ...............so what was wrong ?? who knows.
One thing that does spring to mind is that I left the heater with the power disconnected over night as I was intending to remove it today, so perhaps there was a software clich or the output transistor or what ever supplies the output to the dosing pump was stuck for some reason I dont know, all I do know is its working again and I'm a happy bunny once again.
I have to admit I dont like it when I dont find the reason for something not working and then working again for no apparent reason
![Confused :?](./images/smilies/icon_confused.gif)
but hey ho its working for now, and I now know where the pump is and what connector does what which is always good.
ChrisB