Another problem has occured with my mates 620 Diesel and he is asking me for help again. This time its electrical, if the ignition switch is left in the on position for any length of time a certain fuse keeps blowing and this prevents the starter motor from operating. Nothing else is affected. I suspect a heater plug may be breaking down and causing a short to earth but any help or advice would be appreciated before I am forced to dive in with the old multi-meter.

Further to my original posting, I have just called in on my way home to have a quick look at the car and something else is evident. There is a clicking sound coming from the injector pump whilst the ignition is in the on position. It sounds like a solenoid valve dropping in and out very quickly. There appears to be only one wire going to the pump and that is connected to what looks like a sensor or solenoid. Are these parts prone to failure? How can I test it? and are they available as a spare part? The fuse that blows after after about 30 secs protects the ECU according to the details in the fuse-box

What size fuse is blowing?

The clicking noise from the pump is entirely normal

Its taking out the 15a fuse that according to the fuse box protects the ECU. It blows repeatedly after about 30-60 secs with the ignition is in the on (dash lights on) position. However if the engine is up and running within this time the fuse stays in. Assuming there is no direct short to earth, and I think this is unlikely given the circumstances, the only component in the affected circuit that could take anything near that sort of current without the starter motor operating would be the pre-heaters. The car has done...wait for it....160k! so anything could be possible. I am curious to know what controls the heaters and what governs how long they stay in. I am sure the fault is related to them or the relay but I would appreciate your comments and any advice.

Something pre-heat wise is causing this problem

May be worth checking the engine wiring loom for chafing damage - this is very common around the cam belt cover and fuel injection pump :err:

Cheers Dave and thanks for the advice. I will have a look in the next few days and let you know what I find.

OK well I called in on my mate tonight (on the way home from the local) to have another look. I checked the loom for chaffing damage and I found it had been repaired in the past, I re-insulated the cables using a good quality insulation tape. I then went to check the heater plugs and the cabling to them.........I thought it was the 4 pints of Trophy bitter at first , but after a double take I found one of the heater plugs was missing and so was the cable, so it cant have fallen out on its own! It is the one on the R/H side directly behind the injector pump! I think maybe someone has had a go at replacing it in the past and sheared the bloody thing off. To replace it means the head has got to come off, the broken plug will have to be drilled out and the hole will more than likely have to be helicoiled. Can anyone give me a idea of the approximate cost for a job like this?

Is it an early one?

If so, there are only three glowplugs....off, I know.

Nothing to worry about Sledge:bandit: