Re: Honda BF 130 A Fuel Pump Problems
Given that none of the good Honda technicians on this site have tried to help you yet, here are some suggestions:
1. You know that the fuel pump will run if 12v is applied directly to it (it ran when hot-wired), but do you know if the main relay is supplying the same 12v? Measure for the presence of 12v at the fuel pump (blue/yellow +, black -) when the key is ON. Make sure you're measuring at the same points where the hot-wired 12v was applied.
(a) If 12v is supplied to the fuel pump via the main relay, but the pump will not run, then something is really awry. Suggest you repeat the hot-wire test since 12v supplied via hot-wire or through the relay should both run the pump. Check for loose connections at the pump.
(b) If you see a reduced voltage at the pump when supplied through the relay suggest you check for high resistance connections between the relay and pump since high resistance may not be allowing sufficient current to flow to run the pump.
(c) If no voltage is present, then it's not being supplied by the main relay and you need to find out why.
2. Is the main relay being actuated by your ignition switch? Can you hear the relay click when the switch is turned to ON? Do you measure 12v between the main relay black/yellow and black wires?
(a) If the main relay doesn't click and you don't get 12v, then you need to check your ignition switch for loose connections and the presence of 12v at the BAT terminal (white/black wire). If there's no 12v at the BAT terminal, check your 10 amp fuse. If there is 12v at the BAT terminal, does it show at the LOAD terminal when you turn the switch to ON?
(b) If the main relay does click and you do see 12v between the main relay black/yellow and black wires, then you need to check if there is 12v between the main relay white/black and black wires, then between the main relay blue/yellow and black wires. If there's no 12v at the main relay white/black wire, check your 30 amp fuse (the one with the white/red wire connected).
Hope this helps and that somewhere along this troubleshooting you find the problem. The simplest seeming thing would be a blown fuse, but then the question of what caused the fuse to blow remains. If you do find a blown fuse and the replacement fuse does not blow, you're still not in the clear - the problem may be intermittent. Just carry additional spare fuses until you've finally found the pinched/chafed wire that caused the fuse to blow.
Good luck, Happy New Year.
