Help wiring a fuel gauge...

Update: I went and touched a combination of wire to the battery terminals to see what it does. When I touched the orange and black, I got the back light to the gauge - that's great. When I touched the yellow/white the same thing happend, thus, one must be for taking power in, then the other connects to the sending unit to power it, leaving the gray one to be the one that conects on the other side of the sending unit.

When I accidentally touched the gray and black I got a spark! Does this mean I damaged something?

 

Anybody?

 

please don't touch wires to the battery that might go into the fuel tank

 

Anthony14, drop the bike now and back away!

 

guys, this was nowhere near the gas tank when I did it lol. The wiring I am talking about never enters the gas tank, come to think of it, no wires enter the gas tank...

This is the sending unit I am using -

And this is the gauge - http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0236348702


I have no idea how the sender unit works cause there is no float (any ideas?) but my gauge will connect to that and hopefully give me a fuel reading

 

Anthony14, there are only two kinds of fuel gauges, electric and Pixie dust and the Pixies stopped making dust a long time ago

 

lol, but they worked so well

But really, I keep banging my head on how it would work with no float. How does it tell if the fuel is low or not? Pressure in the tank?

 

my guess would be it is for a low level light,when senser on bottom is covered no light,when senser is no longer covered low level light

you probably have a + wire a - wire then a seperate wire doing to light,that somehow resistance changes between being covered,or not covered with fuel,without having sender in my hands to look at and check with ohm meter,this is just guessing

 

Ok, well as long as it works somehow I'll be happy lol.

 

is that a hollow tube running from cylender looking thing on bottom to top??

 

No, it's a solid piece of brass or steel.

 

the one that goes into bottom its either a tube or wire it looks like a small hose in pic

 

Anthony the sender in the photo is for a Yamaha but the gauge is for a Harley! You're just wasting you time since there's no way those will ever work together.

 

Really? I know the wiring is different but wont they still work it wired together properly? Why would they not work, they both came from China lol

But seriously, doesn't only the ohms rating on each have to be compatible? (I do not know what the rating is, I plan on just doing a mock-up and seeing what it does.) But just cause they have different names stamped on them should not mean they won't work.

Old-Grunt - that's a wire, I though you were talking about something else...

 

With a little engineering, you CAN get them to work together. The trick is to know what you have and the characteristics of both the sender and gauge in terms of resistance and operating range. Resistance matching is not rocket science.

 

Ahh crap, I mocked wired them up and I got the back light to come one, but the little 'arm' did not move at all. I think I broke the dam thing when I did it the first time.

Anyone know what the resistance is for the sender unit I am using? I think it is from a XJ750, I can't remember as I bought it a long time ago.

Or can someone suggest one that would work for sure?