2005 F4i.

The high beam cut power to the fuel pump and now it won't turn back on. Fuel pump works fine when I run power to it directly, but it's not getting power through the harness.

I bypassed the bank angle sensor but that didn't work.
Battery is perfect. Cranks the motor strongly.
Charging system is good. Motor cranks perfectly fine.
Swapped the 2 relays in the tail, and both click when I hit the On switch.
Unplugged the high beam bulb, hit the high beam switch, and it cut power to the pump.
Power loss is only to the fuel pump.

Some time back, I had issues with the Kill Switch where I had to click it a bunch of times to turn on the fuel pump, but that problem went away. Now, the high beam switch is what would shut the bike off. Then I'd have to click the kill switch a bunch to get it to prime the pump. It would eventually work, but this time it won't prime the pump at all.

I suspect a short at one of the switches. Should I just start cutting wires and bypassing the high beam switch and kill switch?

 

bypass the high beam switch and see if it goes away. I do suspect that its a problem in the kill switch however, as that is way more common.

 

I thought this would be a useless test, but now that you mention it, the high beam switch could be constantly messing with the kill switch. I'll try it when I get back from my trip.

 

I diagnose and fix cars for a living.

if a part is constantly giving you an issue, you need to eliminate that part on order to keep going.

Yes, its not always that simple, but in this case every time you hit the high beam switch, it kills it. No question. If bypassing it still kills the bike, its clearly not the switch, but wiring from the switch to the rest of the bike. if its bypassed and it never dies, you know its the switch

 

Replaced the high beam switch and the start/kill switch and bypassed the bank angle sensor. Still won't power the fuel pump. Double checked the fuel pump again by running power directly to it from the battery and it primes. Something is preventing power to the pump's wiring harness.

 

I think I'm going to bypass the entire front end, headlights and all, and see if power gets to the pump then.

 

do you know if its missing power or ground? Both of them need to be there for the pump to go.

I would make sure that the pump is getting a good ground too.

 

As far as I can tell, it's missing power. If it's missing ground, it's just at the pump. The common ground wire is allowing other connected devices to work, such as lights, etc. What I might do is check the voltage at another device using the ground wire to the pump to make sure it's a constant ground. I'll check for power using the frame as ground.

Also, I'm looking for some used relays to try them out.

I ordered a fuel pump because the old one had wiring issues which I've bypassed temporarily for testing; it works when I apply direct current from the battery.

 

FIXED!! I can't believe it was something as simple as a fuse to the pump relay. It's a yellow 20 amp fuse that is housed separately next to the rest of the fuses, which is why I overlooked it. It was pretty fried.

Now, the question is why did the hi beam set it off intermittently? I'm going to study the wire diagram and try to figure that out. Currently the bike turns the fuel pump with and without the hi beam. Hopefully it was just a worn out fuse.

I'm going to reassemble everything (I took everything apart to test the voltage at different components) and ride the bike for a few months and see if it ever happens again. If all is fixed, I'm going to sell the bike to pay off some debts. Other than this, she's been very reliable.

 

I ran into another problem that was cutting off power to the pump and the headlights and blinkers. The large connector between the main harness and the wire harness that goes to the headlight relays (located right behind the left headlight) wasn't making good contact at one of the pins.

I isolated which pin/wire wasn't making contact by testing the power input in both sides of the connector while the key on the On position, but while the headlight was off. Power went to all power wires on both sides of the connectors. Then I tested the ground wires by touching my volt meter to the + post of the battery while using the connector's ground wires for ground. The green wire grounded fine on the main harness side, but not on the headlight side. When I'd squeeze the connector with my fingers, then both sides grounded.

I fixed it by cutting the green wire on both sides and crimping a separate connector for that wire. Now everything works just fine.