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Discussion Starter #1
hey on my 85 shadow 700 i cleaned the carbs today after running out of gas (long story) all was clean inside
my fuel pump however....
if i use a jumper wire siright to the battery fuel will shoot out strong but without the jumper wire with the bike in the "run" position while pressing the starter button i get no gas shooting out.

i used a test light on the pos wire going to the pump and when i switch to run it will turn on for a few seconds then go out, then when cranking it will flash (dim light) but as soon as i stop cranking it goes out....any ideas?

is there a relay? if so i couldnt find it anywhere under the seat....does it look like a typical square automotive relay?

sorry about the long post, thanks for your help
 

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Not a long post--you should see some of mine:mrgreen:

ok ive got a link to an 86 shadow 700 wiring print
http://www.tandj.net/~jpoirier/downloads/1986_VT700_Schematic.pdf


heres a link to a site for you year range, it has a manual you can download
http://home.comcast.net/~retrocruiser/838485/




from looking at that print--you seem to have 4 wires off the fuelpump--a blue, a green, a black , an black with yellow stripe----

-blue runs down and splits--one side goes to spark unit in the back fender and other side goes to the front coil
-green splits into many things an is tied into the Main ground harness
-black runs and splits, one side goes to regulator/rectifier other side runs up to start button with the #7 fuse in between.

this tells me you need to first check that #7 fuse, then you need to check your front coil--these would be the first things i would troubleshoot--i really suspect that fuse because its the only thing in line that would cause you to hit your start button and get no power to the pump, iguess it could be bad contacts or wires in the start switch or wires in between but check that fuse first.

When you tested the pos wire with the light--do you mean the blue wire? if so it sounds like that circuit is fine cause it goes to the coil and spark unit hence the light on, then the flashing (ie coil)

better check the black wire by pulling it loose from the pump, connect test light, hit start button and you should get 12V on the black wire

Hope this helps--let us know
 

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Discussion Starter #3
thanks! is that number 7 fuse under the cover for my "dash lights" or are there more fuses in another spot?
the blue wire is the one that gets power on the pump, i assume the black is a ground?
 

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according to that print from the '86---yours is prob the same

green is the ground

black is the hot from the switch and the #7 fuse and the wire you should be checking

blue is the hot from the coil and gives the pump its pulsing action--(this wire seems to be doing what it should according to your original post)

Check the black for power when the start switch is pushed--if you get nothing then its a good chance its that fuse

that fuse should be right there with the neutral light, headlight, tail lights, turn signals and fan fuses-----its the last one in the line 10amp ignition fuse----on my bike its near the battery on the left side.

it seems like if that was blown though then the start button wouldnt do anything---but check it out and make sure
 

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The fuel pump does not run continuously. it pulses somewhat slowly. When cranking the bike you should get fuel in spurts not a steady stream. the spurts can be 5 seconds apart.
 

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Discussion Starter #6
So I have a black and a blue wire comming off the pump. Isn't one ground and one pos? I assume black is ground right?
 

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so you only have 2 wires coming off the pump? is that correct?

we need to find a wiring print for an '85 700 then----the '86 must be different

can you see where the blue wire runs?---Did you find that fuse?
 

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Discussion Starter #8
Yes only 2 wires. I found the fuses between the tach and the speedo. They are all brand new and good. Would it harm the bike to wire in a switch to the fuel pump so I can turn it on before riding then cut it off after. Or would that flood it out at low rpms ?
 

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so you only have 2 wires coming off the pump--is that correct?

we need to find a wiring print from an '85--the '86 must be different

how does the pump body mount to the bike? maybe thats its ground and the blue and black are like i said

did you find that fuse?

can you see where the blue wire runs to?


whooops repeat sorry
 

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no that would prob be fine----it just pumps at the same rate all the time, the float valves in the carb shut when the bowls are full and put a back pressure on the pump that cuts it off i think----ill try to find a wiring print for your bike--it may be something very simple
 

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Discussion Starter #11
Thanks man I really appreciate it. I'm at work now but I'm going to tear into the wiring as soon as I get off and if I can't figure it out ill be putting in a switch I guess
 

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Found in another post on this site = not mine:

Click this bar to view the small image.



Looks like on this the ful pump does have 2 wires---a black w blue stripe and a green

One does run to a fuel cut relay and looks tlike the other green runs to another relay but yes the green appears to be a ground of sorts, I dont know what the **** a winker relay is---looks like a blinker relay) but they appear to share a ground with the green wire----maybe its so dark green that it looks black.....

My money is now on that fuel cut relay----mine is on the right side near the battery box with a couple of other auto style box relays

pump is only supposed to pump when the bike is running or the start button is pushed---find the relay and pull the connector off---jumper the black and the black/blue wire on the connector with a paper clip----then flip the key, your pump should run--if it does run,,,, then the relay is bad and you can run it with the wires jumped like this if you want to-----its just a safety feature so the pump cuts off if the motor quits---your pump will be pumping everytime the key is on with it jumpered
 

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Discussion Starter #13
thanks for finding that! you have been really helpful; i ust got home from work and im going to try and find that relay...wish me luck, ill let you know what i fine
 

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Discussion Starter #14
esj001 you are awesome! i put in the paper clip turned the key and bam! fuel everywhere! hooked up the gas hoses and she fired right up! thanks so much for your help! i guess i should try to find a new relay...any ideas on where? for now i will rock it with a paper clip!
 

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thats great man----i dont know why i didnt realize thats what was going on earlier--the 86 model doesnt have a relay--so i figured the 85 surely wouldnt-----my 03 has this relay wired up pretty much just like yours-----in my case i had a bad a fuel pump but the relay was good---this method of testing is right out of the manual----

here is one at bikebandit--they usually have fair pricing--LOOK at #17
it looks like its $64.82:shock:----i bet you could rig an autozone relay in there

1985 Honda VT700C SHADOW Parts, 1985 Honda VT700C SHADOW OEM Parts - BikeBandit.com


if you look at one of my first posts about my fuel pump going bad--we discuss this relay----talk about a long winded post:mrgreen:

http://www.hondashadow.net/forum/72-technical-discussion/106531-fuel-pump-intermittent.html



basically i dont see anything wrong with rolling with the paperclip----like i said its just a safety feature so if your bike quits running in a crash it cuts the fuel----so if you have a wreck, and your key is still on and the fuel line breaks, and your passed out on the road i guess you could have fuel pumping out all over your lifeless body which wouldnt be good--------but if you arent worried about that......

there are a lot of gravity fed bikes having wrecks without bursting into flames, so i think you will be ok
 

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yes, just search for fuel pump relay jumper. there is even a post with a picture. It is a three wire connector and you wire the hot to the pump feed. This will not hurt the pump to run this way.

that said, without the relay the pump will run without the engine running and this could result in a fire in a crash.

I take that chance, but i did wire a standard relay that is powered from the kill switch so that I can stop the pump when the bike is down on the left side where the key is located.
 
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