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Discussion Starter #1 (Edited)
Hey y’all! I need Melatv lol to help me test wiring. I have no power to my fuel pump.
08 Honda 420fm
I bought this harness off eBay and it was a little beat up so I’m thinking I have a broken wire somewhere.

It has a brand new oem never used fuel pump. I have clicking at the throttle body. I have spark and power everywhere but the fuel pump and swapped with a known working pump for good measure but still nothing. Swapped throttle body fuel pump rely and ECU and still no change. Brand new battery with 12.5 volts.

I do have an after market key switch on it. Could it be that?
 

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Discussion Starter #2
It’s not the key I tried a different one.
The accessory plug was cut off tho so I just taped the two wires so the didn’t touch.
Could that be it?
 

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does that model have a bank angle sensor ?. if it does ?, that might have something to do with why your not getting power to the fuel pump ?. check the service manual :).
 

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Discussion Starter #4
Bank angle sensor does cut power to the fuel pump but not initially. It would still prime when you turn the key on and mine doesn’t.
It also cuts power to the start button but I have that so the sensor can’t be it. 😞
 

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Bank angle sensor does cut power to the fuel pump but not initially. It would still prime when you turn the key on and mine doesn’t.
It also cuts power to the start button but I have that so the sensor can’t be it. 😞
have to checked all the fuses ???. checked all the diodes ?. i'm wondering if this has anything to do with the ignition switch ?.
 

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Discussion Starter #6
I tested the fuses they’re good bit I don’t know how to test the diodes.
I tried another key switch no change it’s aftermarket too but....
 

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I take it you’ve unplugged the fuel pump and powered it up separately? I know you say it’s new or low hours OEM but these donsuffer from pump issues.
 

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Discussion Starter #9
I got it! I cleaned and added dielectric grease to the throttle body and airbox connections and it worked....... how many friggin times do we say it a day to clean those connections ... you’d think that would have been the first thing I’d do! Hahahahaha (laughing at myself)
Thanks y’all!
 

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I got it! I cleaned and added dielectric grease to the throttle body and airbox connections and it worked....... how many friggin times do we say it a day to clean those connections ... you’d think that would have been the first thing I’d do! Hahahahaha (laughing at myself)
Thanks y’all!
here'sssssssssss yer sign ?!..lol. ( don't lose it..i may need it back later on ! )
 

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I tested the fuses they’re good bit I don’t know how to test the diodes.
I tried another key switch no change it’s aftermarket too but....
diodes let current/voltage flow in only one direction. to test, you have to make sure, diode, is disconnected to the circuit, on one side, so you dont get feedback, from the other side, of the circuit. then all you need is an ohm meter. it shout read open in one direction, closed in the other. my amprobe also has a continuity sound function. all that means is, when your leads are the front an back of an object, you hear a sound if voltage can get through, when you reverse the leads, same thing.. if you hear a sound both ways its a short, if you hear nothing both ways its an open, how ever, if you hear a sound going the way the voltage is supposed to go it is a good thing. if you hear a sound the other way it is not. same goes for not hearing a sound.
this needs much editing. i am not good at explaining things.
 
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