306 Hdi Intermittent Starting Problem.

I have a 2000 model 306 Hdi, Occasionally it refuses to start.

The first time it happened, the AA guy that came found no firing signal at
the injectors. He found that the voltage at one of the fuses ( I can't
remember the circuit, but I can find it when needed, see later) was very
low, at about 5 or 6 volts.

To start the car, he linked the fuse directly to the Battery positive and
then started the engine. Once started the jumper wire was removed and all
went well, for a few days.

At the next service, the PUG garage connected the diagnostic computer ( at a
charge of £25.00 ) and then "updated the software" as a cure? That worked
for a couple of weeks, then the same again. The only way to start the car
when it is playing up, is to link the 2nd 15A fuse from the bulkhead to the
battery +ve, then crank. removing the link once the engine is running.

Any ideas what is going on please ? ? ?

 

It's not intermittent anymore!

I have about 3 Volts at the number 34 fuse in the engine bay, my owners
manual says that this is the "Petrol Pump". The fuse itself is OK (Yes I
have tried swapping if for a new one just in case).

Where does the feed to this fuse come from?

Does anyone know where I can get wiring schematics for the Hdi 306 (the
Haynes manual for the 306 does not cover the Hdi variant).

Thanks
Jeb