No Power to in tank fuel pump

[Peebee]

My old 2.0 litre HDi 406 will not start. I could not hear the pump, so having had this fail before, naturally assumed that this had failed again so without testing just ordered a new one and replaced. However, still no joy, so have done what I should have done in the first place and tested the supply to the pump, nothing.
I have gone through all the fuses and none have gone.
Any ideas as to why no supply is getting to the pump would be gratefully received.

[406owner2]

Have you checked the relay itself ? specifically what it's doing, it also could be seen to be faulty, but in actuality it isn't. On my petrol 406 one of the relays in the double relay activates the pump. Also check if the relay is receiving power from it's plug.

I'm still not exactly sure how i managed to get the relay to do what it is suppose to do by the ecu in my car, but my relay now does the right thing and my petrol pump works.

I'm thinking perhaps my car's ecu sensed low water or low oil the shut off the relay, but then again it could have been something else.

[lozz]

Have you checked the Inertia switch?

[Peebee]

Right, I was about to check the inertia switch so thanks for the reply. I have checked the double relay and that seems fine, clicks on when ignition is turned on, then a second click on, after about ten secs one set of contacts switch off, so about to go and check the inertia switch, freezing cold too.

[Peebee]

Voltage getting to inertia switch, but no further. The continuity checks from the switch to the pumps fuse, so surely it must be the switch.

[Peebee]

How do you reset the switch, or do I need to replace?

[lozz]

Reset inertia switch?

just press it downwards,

[Peebee]

Inertia switch it was, thanks for everyone's help.

What a pain in the bum.

[lozz]

Inertia switch it was, thanks for everyone's help.

What a pain in the bum.

ok brilliant,


pay my receptionist on the way out. dont slam the door,

[steve_earwig]

Nicely done lozz

I always forget the inertia switch because I've never had a car with one

[jonsowman]

pay my receptionist on the way out. dont slam the door,

[lozz]

Ithink the Inertia switches,shouid be the first thing people shouid check,

No noise from pump give it a Press. costs nothing,

Some garages wouid Make a meal out of it, a decent hole in the road can trip these off or even giving the bonnet a slam,

[JimH240]

Guys,
Can someone explain what an inertia switch is /does? Where can it be found?

[Doggy]

It opens automatically in the event of severe decelleration - to shut fuel off in an accident.

None of my HDi's have had one, AFAIK, but I believe it is to be found on the nearside front suspension turret, or therabouts. They're usually red......