# Fuel pump wiring problems?? Ecm not supplying ground



## Josh (Nov 23, 2009)

Alright, I've been tracing down my fuel pump wiring problems. I had several corroded connectors on 2 relays. My fuel pump relay, and the other one in the center beside it? Which relay is that exactly? I've traced the problem down to the ecm not supplying a ground to the relay. I ran another wire from the ecm to the relay thinking it might have a broken spot in it. Which is not the case. I checked the ecm grounds, and they are good. Has anyone has a problem where the ecm would not supply a ground to the fuel pump relay but everything else works fine? I can fire up the bike and it will run just fine. I just cannot get the ecm to run the pump by itself.


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## jrpro130 (May 10, 2009)

Hmmmm. I have just had similar problems. I lost power to the brown wire. Try changing the relay. I will look into it also...I feel your pain


Should be wrenching instead of using TapaTalk


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## Josh (Nov 23, 2009)

Well, the relay is good. I can supply a ground to the wire and make the pump kick on. The problem is the ECM will not supply the needed ground. I've never heard of an ECM all the sudden not supplying a ground. Unless the ECM was bad, which the bike runs fine minus this problem.


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## Stimpy (Jan 26, 2012)

Try by passing the relay all together just in case. I had a bad relay that tested good on every test we could do to it. Jump your yellow red and white red wires together and try it.


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## jrpro130 (May 10, 2009)

Well the short and long of it is that is exactly what happened to me. My brown wire is not connecting somewhere between about 6" from the ECU to around the shifter. It looses connection. So I bypassed the wire in the loom and just went straight to the connector.

I would try to just run an external line outside of the wire loom


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## Josh (Nov 23, 2009)

I tried to jump the wire an inch from the connector on the ECM. The ECM will not supply a ground. I change out the relay with a regular auto parts store one. I've narrowed it down to the ECM will not supply a ground at all the wire traces good from the plug back to the relay.


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## jrpro130 (May 10, 2009)

But everything else works on the bike? So you must still have a ground 


Should be wrenching instead of using TapaTalk


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## Josh (Nov 23, 2009)

I'm supplying the ground to kick on the pump. I checked my grounds all are good. Anyone ever seen an ECM that worked fine but wouldn't supply a ground? Might try to swap out ECM with another bike. That will tell me a lot.


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## Josh (Nov 23, 2009)

Anyone know what the other relay in the center of the bike is?


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## Stimpy (Jan 26, 2012)

If its the one with the blue wires it's the fan relay.


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## Josh (Nov 23, 2009)

Figured I'd update with what the problem was. Changed the ECM to another one which supply's a ground just fine. So the ECM was the problem. Worked fine besides not being able to supply the ground.


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## saskskeg (May 30, 2013)

I have same problem I jump the white red to the yellow red and bike runs fine but put relay in and pump will not work so ECM must be junk. Will this cause the bike to back fire and run like crap


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## Paul S (Oct 25, 2021)

FIXED MINE! Tested all the wiring. Tested the ECU(serveral times) ground, positive, wiring going to fuel pump relay. Finally determined what I did not want to hear. BR/Y pin 30 from ECU to relay was not sending signal. Bad ECU. Found a used one for $300, as opposed to $630 for new. 5 minute install, all good. All started at fuel pump filter. Completely clogged. It would freeze the pump motor.Popped the tank with a rubber mallet. It would work for a bit, finally quit. Replaced the pump but no juice. I assume the old frozen one caused the ECU to stop throwing the signal. New/used ECU fixed the pump signal. Hope this helps someone else. The pump filter is very fine screen and small. Every one should change it once a year at least. Not that hard, just time consuming. Enjoy the ride!


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