Vulcan Drifter Riders

DISCUSSIONS => Drifter 1500 only => Topic started by: Slytherin_Drifter on January 18, 2015, 12:54:21 PM

Title: fuel pump wont kick on
Post by: Slytherin_Drifter on January 18, 2015, 12:54:21 PM
Ok so i finally got my bike back together. Get everything hooked up and she fires right up. But i notice that my fuelpump isnt kicking on when i turn the switch. If i play with the connections on the back eventualy it cuts on. Anyone got any ideas
Title: Re: fuel pump wont kick on
Post by: Troll on January 18, 2015, 13:10:30 PM
connections on the back of what?
Title: Re: fuel pump wont kick on
Post by: Slytherin_Drifter on January 18, 2015, 13:19:53 PM
Sorry. Connections on the back of.the switch. Red black and white
Title: Re: fuel pump wont kick on
Post by: Troll on January 18, 2015, 13:58:54 PM
You have one of the aftermarket switches? If so it's the same old issue with the resistor. If it's a factory switch, you may need to replace it. Here's the thing...and I learned this the hard (read expensive) way. There is one pin on the computer that is listed as no connection. In reality, it's a low voltage signal from the ign. switch. If it doesn't see the correct voltage, it won't ground the fuel pump to turn it on...The thunder switch that most people replaced the OEM switch with doesn't have this resistor, so you have to add it in. The wiring harness that comes with the thunder switch has the resistor in it, but they fail and/or loose connection, so the pin on the computer doesn't see the correct signal
Title: Re: fuel pump wont kick on
Post by: pcarrell on January 18, 2015, 21:06:49 PM
(https://www.vulcandrifterriders.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv430%2Fcsmithc0%2FWeAreNotWorthy.gif&hash=0ed15697582d0628193cafd4ece6c3251e080a58)
Title: Re: fuel pump wont kick on
Post by: John Hopkins on January 19, 2015, 13:13:36 PM
I think that resistor is designed as an antitheft device so that a thief can't just link the ignition wires to steal your bike If I remember correctly it is something between 100 and 400 ohms, maybe troll can get a bit closer on the value, if not start with 100 ohms and see how you get on from there..

Resistor color codes are bk br r or yl gn bu vio gy wht with bk = 0 up to wht = 9 so first color is first value, second color is second value and third number is the number of noughts or the multiplier..

Some resistors have an extra value band and are called four band resistors, the way to tell the difference is  three band resistor have three color bands close together and four band resistors have four color bands close together..There will be an additional two colors at the other end of the resistor but you don't need to know what they are for.

John.
Title: Re: fuel pump wont kick on
Post by: Slytherin_Drifter on January 19, 2015, 16:57:34 PM
Ok i realize that when i turn the switch the relay.clicks. does that mean anything
Title: Re: fuel pump wont kick on
Post by: Troll on January 19, 2015, 18:57:05 PM
Quote from: Slytherin_Drifter on January 19, 2015, 16:57:34 PM
Ok i realize that when i turn the switch the relay.clicks. does that mean anything
Yes and no. Is this an aftermarket switch? The main relay is powered on with everything else...BUT the fuel pump is grounded through the computer. If the correct voltage is not seen on pin 6, I believe it is, then the path to ground is not completed. It is an 18 ga wire, yellow with a green tracer, as I remember. It DOES NOT show up in any wiring diagram, but if you pull the computer out, it will be there. John is correct, it's an anti theft measure found ONLY on EFI systems. I had a picture of that I posted last summer, so if you search my posts, you will see we have had this discussion before...
Title: Re: fuel pump wont kick on
Post by: Troll on January 20, 2015, 10:52:17 AM
Here's the circuit: