Fuel Pump Wiring

Hi All,

Thought it may be a good idea to join a forum and ask if someone can help. Electrics are not my strong point but had been going fine until I tried to reconnect the fuel pump...there was nothing wrong before I started my project!

Story so far is that I have chopped the rear off my 91 efi and am nearing completion of a tubular frame etc, shortening it for off road. I've reconnected the rear lights after chopping down the loom (carefully) which have worked fine. I've also binned things like the electric sunroof...

The problem seems to be the black wire which is one of the three wires in the connector block to the pump. I cut the wire when stripping things, thinking it was an earth / neutral and planned to connect it to the chassis...its not. I now cannot remember where it went, only recollecting it connected to another wire which did not seem to go anywhere as they had a ring connector joining them?

Have tried putting temporary connections across all the wires that have been cut, and back to the pump relay. In some instances the pump does run, but does not run then stop as I recollect it doing before. Seems I may be giving it a continuous live, but thats me guessing so thats why I'm hopeful someone can steer me!

Will be happy to provide more photos if that helps, just say. So now I'll wait to see if someone can help out...it will be much appreciated!

Thanks

Colin

You only need 2 wires to the pump, ground/chassis and feed from the pump relay. Usually the ground wires on Rangies are Black and your recollection that the suspected black wire was connected with others to a ring terminal tends to confirm this. You should have a wire in the vicinity of where the pump used to be which is the live feed, connect a meter or test bulb to the wire you want to check and ground, switch the ignition on..it should light. Go to the fuel pump relay or fuse and remove it..the bulb should go out or the meter read zero.
I don't have the Classic wiring diagram handy at the moment but I will check tomorrow and let you know the colours.

I feel that the pump should run continuously as excess pressure in the fuel rail is returned to tank.

Hi,

Thanks for your thoughts, I'm just in from another session trying to solve things. I did get some success, in fact may have solved it by fitting an intermediate section of loom which I had removed. It is essentially three wires between two plugs. Its a case of fitting males into females...I did not think removing this would have made a difference except it appears the plugs go together in a way which rotates the wires, meaning the connections are not what you thought.

Interestingly the black wire was left disconnected, although I did connect the ground from the pump body...I need to put some petrol in and try and fire it.

Seems two wires plus the ground are doing the job. Perhaps one of the wires is the inertia switch I have read about, although I have not come across it when looking under the seats. Or an auxillary live...but at least I'm getting something from it.

The loom also seems to use a variety of coloured wires along its length (its a standard loom) which is fun for an amateur like me...I'm also totally colour blind ha ha

I will post something more once I've tried to start it!

If you get any wire colour info i'd be interested to check it as best I can against what i'm doing.

Thanks again

the inertia sitch is under the passenger seat , as you look at back of seat it is on the right hand side. has a small round black button on it. unless for some reason it has been removed that is

Looking at the circuit today, the wire from Fuse 18 (Fuel pump fuse) is White & Blue to the pump. Other wire to the pump is Black (Ground/Negative).
Hope this helps.

:behindsofa:

cheers, that accounts for two of the wires! Not going to worry about the other two as long as it runs...

Without looking further, I imagine the other two are for the fuel gauge and low fuel level warning light.

Hi,

Just thought i'd let you know I got it started successfully today. Gauge and warning light operated correctly too.

You are probably right about at least one of the other two wires being for the gauge and warning light - I had not thought of that! That would then confirm the white and blue as the pump motor positive having checked it back to the pump relay.

I did go with my hunch and connected both black wires as neutrals, which seems correct as everything works. I can only think one is for the pump motor and the other is for the gauge / warning light...

Hope this helps you in the future!

Colin

PS could'nt get it working on gas although the solenoids were operating...then after two hours realised I had forgotten to reopen the manual tank valve (having removed it over a year ago). It then ran like a beaut!

Good Man !!!:clap2::clap2:

Pleased to see you got it sorted.
One thing we like to see on here is the outcome, good or bad, regarding problems.
Well done !!