Fuel tank pump P38 dHSE

Hi

I have strange (to me) problem. After I switch off, there is still a buzzing sound from the rear of the vehicle - around the area of the fuel tank.

I haven't noticed this before tonite, but it can be heard (in a quiet street) from 12 feet away.

I had all the brake discs and pads replace last week and have since had morning starting problems, that I put down to them leaving doors open etc and leaving the battery low. My daily 'run' to work since is only 4 odd miles so I assumed that it could still be low until I noticed the buzz. So I am now guessing that the pump is discharging the battery.

Anyone able to confirm that the fuel pump can run with ignition off and if so why?

P38 dHSE 1999 model, fuel pump changed 5 months ago due to faulty gauge sender. Everything else works fine except the clock! Getting 32 mpg @ 60 mph, so can't be much wrong with it

So any ideas please?

An update - I had a :doh: moment and realised that the pump relay must be closed circuit for the pump to run constantly. So I checked this am and found it very hot and when I pulled it - the buzz stopped so I am getting a new relay. When I put it back in it jumped started first time, but the buzz remained after switching off (and pulling the relay stopped it again!)

Only worry is what could have caused the relay to fail or is it just one of those things?

As I said :doh:

Could be a fault with the fuse box
take it out and see if you can see any shorting or smell any burning etc

Look on the side of the relay it should give a diagram of which are the activation terminals and which are the switchable terminals. Put a continuity tester across the switchable terminals if there is continuity the relay is duff. The fuel pump is activated by igintion key then when engine runs is pulled by a current direct from the alternator using polarity reversal. If the switchable terminals are open circuit. Check the pins in the fuse box corresponding to the activation circuit if these are live with ignition off you may have a fuse box problem.

Thanks guys

I now have in my hot little hand a new relay, so I'll try that later.

There doesn't appear to be any external signs of damage to the relay/pins or the fuse box, but I will check as Wammers suggests that there isn't a hidden short or other continuity problem.

Hope theres enough 'kick' left in the battery to fire up and get me home!

The joys of p38ing!

Final Update

No damage or short on fuse box, so I put in new relay - no sign of pump running so all seemed OK.

After allowing usual delay for glow plugs, fired up on slight movement of key as normal.:5bhurray::5bhurray::5bhurray:

Checked over with FCR - no faults recorded - all back to normal

Until the next time............