Anyone rewound a gas gauge sender coil?

[t3rmin]

So my gas gauge would drop to empty after 1/2 tank or so. Pulled the sender unit (float and such) out of the tank and found the wire of the resistance coil thing had been worn through by the wiper arm. So the wire was disconnected about halfway along the coil and naturally once the wiper got to that portion the gauge drops to zero.

Anyway, I tried rewinding it with some small gauge wire I had around the house. Was pretty proud of my work, but it doesn't work right since the resistance values are all wrong I guess. Different gauges and metal compositions have different resistances I think, and I've got to match the original in gauge/composition and length to get the right resistance and thus the gauge be accurate.

So has anyone done this? Can you tell me what kind of wire to use and how much? Seems a shame to buy a whole new sender when this could be a quick & easy fix.

[80GS750]

i have no idea. you will have to take the original wire and try to get a length on it, and also see what gauge wire it is. itll have to be a pretty close match.

[Dave8338]

I agree on the "fix it when possible", but in this case and having no experience in the rewind department, I'd opt for the new / good used unit. :?

[t3rmin]

Well the original wire came off in a zillion pieces, so measuring it won't be possible. And I've got no way to determine type of metal.

Also, to add to my already lofty requirements, the wire would need insulation that's gas proof. ;-)


C'mon, I know there's some electrical gurus here!

[SPARKSS]

Howdy t3.....A fellow fearless experimenter - I like it! The wire used to make such resistances is indeed a special wire having significant resistivity (resistance per unit). As you probably wound with copper your gauge will hover or be stuck at one end of the range most likely. You said the wire came off in a lot of pieces (each turn or 2 I'd expect) and this pretty much dooms your project. I've wound similarly small coils before and usually try to measure the resistance first (even from ends to the breaks) and count the turns if at all possible before or during disassembly. Tedious and time consuming and not for the short fuse personalities

A factory manual may indicate the resistance of this coil......measuring one of the tiny segments physically will give you the gauge and measuring accurately the resistance of the longest segment you can and extrapolating that will give you a rough length. Look up resistance wires......best of ruck

[t3rmin]

I think the manual does mention the resistance. Actually I've seen the value on the forums too I think. One thing I've got going for me is the windings core has residual imprints of the old wrappings so I think I can get pretty close to the original number of turns. Just gotta find the right wire. Think RatShack would stock resistance wire?

[t3rmin]

Or maybe there's some other material I could replace the coil with? Something with resistance that increases with length?

[t3rmin]

Looks like resistance wire is usually nickel chromium (nichrome). Local Ratshack doesn't have it. I saw a suggestion to use guitar strings which have a lot of nickel... I do have some fine gauge electric guitar strings which I'll test for resistance...

[Billy Ricks]

Which bike do you need it for? I'm not using a fuel gauge on my 700 anymore and have no need for it.

[t3rmin]

Which bike do you need it for? I'm not using a fuel gauge on my 700 anymore and have no need for it.

It's the 700. I'll take it off your hands if that resistor coil looks good (inside the little metal box on the float sender unit)!

[Billy Ricks]

It's the 700. I'll take it off your hands if that resistor coil looks good (inside the little metal box on the float sender unit)!

It worked the last time I had a gas gauge. I'll take it out in the next day or so and check the windings. If it's good I'll just snip the wire so it remains as long as possible so you can splice it to yours.

[t3rmin]

It worked the last time I had a gas gauge. I'll take it out in the next day or so and check the windings. If it's good I'll just snip the wire so it remains as long as possible so you can splice it to yours.

I'll take as much of the whole assembly as you can spare. You'll need the sealing plate still of course...

The more I've got the more leeway I have with my mediocre soldering skills. ;-) Plus the coil thingy is really delicate...

...and thanks! Let me know how much to PayPal ya.

[SPARKSS]

I know rat shack wouldn't have it around here.... You might try your local appliance repair depots.......that sort of wire is used variously in that trade. Even better, if there's any industrial controls manufacturers in your area, you might drop in and ask 'em about it (especially if you determine a size and resistivity first.....they'll be impressed and may help you out).

Personally, I've tried a lot of similar projects over the years but some questions I'll ask myself before attempting (comes with experience) are "Whats the failsafe of this repair"....."What damage can be done by a bad failure"......"Keeping in mind the first 2, what's the relative cost of a proper replacement". Some things allow for an honest try with low consequences......yours is an electric coil in the vicinity of gasoline.

[80GS750]

careful with the soldering.... it will change the resistance of the wire.

i have 2 gas gauge sending units from 79 gs1000's. not sure whats good on them. your welcome to buy one off me if you need it.

[moto_dan]

Maybe this link will provide some helpful info. Check under tech info.

http://www.resistancewire.com/mainpage.php