Fuel Sender rebuild

[jwgreen]

Hey Guys,

I have disassembled and cleaned up my fuel sender but the really thin wire wrapped around the phenolic cylinder is broken. Can anyone tell me what exactly it is called and where I can find some.

FuelSenderCylinder.JPG

[Coyote Patrol]

Justin, is it broken where it wraps around the cylinder? Or where it attaches to some terminals? If the coils aren't broken on that rheostat i would soak this in some CLR and carefully resolder it back on to its terminals. . This will be a good thread to post. I will try to figure out what senders are out there that we can rob some parts from to make our Patrol senders work again. This is the most common part to go bad on these Patrol senders, im sure there is another vehicle out there that has a fuel sender rheostat that would work.

[jwgreen]

Justin, is it broken where it wraps around the cylinder? Or where it attaches to some terminals? If the coils aren't broken on that rheostat i would soak this in some CLR and carefully resolder it back on to its terminals. . This will be a good thread to post. I will try to figure out what senders are out there that we can rob some parts from to make our Patrol senders work again. This is the most common part to go bad on these Patrol senders, im sure there is another vehicle out there that has a fuel sender rheostat that would work.

Its broken at the connections. It looks really corroded and I would like to try and replace the winding if at all possible I just don't know what type of wire it is exactly or what size. I don't think there is enough to solder it back to the connectors without unwinding a bit of it. I will do a how to if I can find the wire to replace it with.

[Coyote Patrol]

Hope you find something this will be interesting. The final cylinder will need the exact number of turns as the original "or very close" and the correct OHMs reading before you connect it to the gauge or you could smoke test it.

[jwgreen]

Hope you find something this will be interesting. The final cylinder will need the exact number of turns as the original "or very close" and the correct OHMs reading before you connect it to the gauge or you could smoke test it.

Yeah I was just doing some research on that stuff. Looks like it's 100 ohms for mine. Lots more to research before I can check this one off my list.

[moore_rb]

It's probably just really fine gauge copper magnet wire.

Here is a chart of the really fine AWG magnet wire gauges, and their associated diameters and resistance properties:

http://www.hmwire.com/PDF/Bare_Copper_W ... _Sizes.pdf

[Driven]

I think magnet wire has too little resistance. According to the chart you would have to use over 100' of the 40awg to wrap your sender to get 100 Ohms. NiCr wire has more resistance per unit length using the same diameter NiCr wire you would only need 1.5' of wire. Unlike magnet wire NiCr is not typically coated with insulating varnish, so if the sender is wound with each wrap touching the next you will need to add some type of insulating material between the wraps. You can buy insulating varnish in a spray can and coat the wire before wrapping just make sure to carefully scrape off the varnish where the wiper moves across the coils. In order to find the correct wire you need to either unwrap the wire from the sender and measure it's length or count the # of wraps and use the circumference to figure out how long it is. Then find the wire that will give you 100 Ohms for the same length.

[Driven]

Sorry, I wasn't logged in so I didn't see your picture when I first read your post. It looks like there is approx. 160 wraps and while it's hard to tell I assume it's about 0.5" in diameter. That would make the wire ~10' long this is much to short to use magnet wire. I also see that it is wrapped with each turn right next to each other so you will need to use or make coated wire.

[jwgreen]

Thanks for all the info guys, I tried the cleaning method first and all the crud came off and I rechecked it and it still reads about 100 ohms. So now I just need to put it back together!!

[moore_rb]

I think magnet wire has too little resistance. According to the chart you would have to use over 100' of the 40awg to wrap your sender to get 100 Ohms. NiCr wire has more resistance per unit length using the same diameter NiCr wire you would only need 1.5' of wire. Unlike magnet wire NiCr is not typically coated with insulating varnish, so if the sender is wound with each wrap touching the next you will need to add some type of insulating material between the wraps. You can buy insulating varnish in a spray can and coat the wire before wrapping just make sure to carefully scrape off the varnish where the wiper moves across the coils. In order to find the correct wire you need to either unwrap the wire from the sender and measure it's length or count the # of wraps and use the circumference to figure out how long it is. Then find the wire that will give you 100 Ohms for the same length.

Very great points (it's been 20 years since my ITT Tech days )


http://jacobs-online.biz/nichrome_wire.htm