So, I’ve got 2 fuel pumps which work directly from 12volt supply, but neither will work connected to bike wiring harness. I have 2 relays, but neither checks out as per manual- they’re not getting 12v from white wire when starter button pressed as stated in Clymer manual. Is this relay just a safety cut out in case bike is dropped, and cuts the fuel supply?
If so, then I assume I have to have it in the same attitude as it sits in rubber housing to get the right orientation to work properly…
Im getting 12v to the other 2 relay wires when ign. is switched on Have just read an old post (2010) from Planty, who said jump the white to black wires to get the fuel pump to run. Is there a definite procedure to test the relay when out of the bike, as Id like to check both of the relays to know if this is part of, or the complete problem?
Hi Speedy,there are 3 wires on the relay,Black is 12v supply White is the feed to the pump and Blue is the signal wire.When there is power on the Blue the black and white are connected.Supply for the blue comes from an(or on later models the)igniter unit.
If you have 12v at the blue and black and nothing on the white the relay is dud.
Regards Bif
Hi Bif,
great, thanks-will check it out first thing in the morning. We`ve been having chilly nights down to about -6 Celcius lately, but without any of your regular rain, bloody drought…
Cheers
Gooday again VF gurus & or Bif,
so now have fuel pump in place, and running strongly when hot wired at FP relay between black and white.
Neither relay appears to function, but should they kick power to pump just when ignition is on, or does starter need to be cranking before it kicks in?
My next Q is: the factory original relay apparently cuts power when the bike is dropped, if so, then the orientation of the relay in the rubber holder is critical to operation, - should the plug and connector be pointing down towards the road, or inwards 180 degrees to road?
One other strange thing is, my two VF manuals- Honda Factory, and Clymer, show the relay standing up alongside the regulator, whilst mine, (85 F model), sits horizontally above the flasher unit, and it all appears standard undisturbed rubber and plastic mounts???
Hi speedy, the orientation or the relay isn’t important, the relay sends power to the fuel pump when the engine is running or turning over on the starter…
Thanks Pete, but just to clarify, (Ive got up very early this morning), should the relay get power whenever the ignition is on, or does the motor have to be running or cranking? Sorry to be a bit thick about this, but its the last thing to get right before I fit bodywork and get the old girl on the road.
If, as some have suggested, the relays job is to safely cut current to the pump if the bike is dropped, how does it do this- thats why Ive been grappling with ensuring that the relay is aligned correctly? But, from what youre saying is that once the motor stops current is cut?
Hi speedy, you have 3 wires to the relay, black is 12 volt supply and should be live whenever the ignition switch is on, white is the feed to the pump, you seem to have proved these are working as your pump runs with the jumper wire in, blue is the signal wire that comes from the CDI, it is also the same wire that goes to your coils to initiate the spark (low tension side), so your engine has to be running or turning over for the signal wire to throw the micro switch inside the relay.
The safety aspect just stops your fuel pump running if your engine isn’t, example if your bike fell over, the engine stopped but the ignition was still on, your fuel pump would stop running, without the relay the pump would carry on running until it had emptied the fuel tank…
Thanks Pete for persevering with your explanation, I`ve finally got it!
cheers mate!