Ok I got a chance to take a look at my old pump today, I stripped it down to see if I could see any obvious reason why it had stopped working.
The bolts that hold the pump together
With the bolts removed the ECU just pulls away
Make sure the ECU is pulled off squarely so as not to damage the prong that sticks out from it.
The ECU showing the prong
Close up of the ECU numbers
Close up of the ECU Solenoids
Back of the valve block
Motor side of the valve block
The motor just pulls off the valve block.
Motor power connections
The prong from the ECU passes through a hole in the valve block to connect with the motor connections (circled)
I tested the motor by applying 12v to the connection, it burst into life so there's no problem with that.
There's nothing really that can go wrong with the valve block, I suppose the valves inside could be jammed but I think the problem is more likely to be with the ECU, So time to get into the ECU.
I used a Dremel type tool to cut open the ECU, you could just as easily use a hacksaw.
Cut round the edge of the ECU
The ECU with the cover removed
Close up of the PCB
Super close up of the pin connections
After inspecting the PCB closely with a magnifying glass I can't see anything obvious, the only thing that looks suspect to me is the pin connections. These are the backs of the pins that the multi plug connects to, they look like that have just been pressed through the holes in the PCB. The pins seem to be a split design, you can see this in the photo above.
I think I can see some solder on them but it only seems to be a tiny amount and in two places on each pin where it passes through the hole, surely there is more solder than this on each pin ?
Are the pins soldered from the other side of the board ?
I've never seen through hole connections like this before, I would have expected them to be fully soldered to the solder ring on the board.
I hope someone who has seen connections like this before can advise, it would be nice to think that all that was required to fix the ECU was a dab of solder on each pin.
I did check continuity of some of the pin connection to the PCB with a multimeter, the pins I checked are making a contact, but that's in the house at room temperature, maybe when the PCB is cooler and there is voltage present the connections could be failing.