Fuel Sender

[rybad]

Does anyone know what kind of info I will need to replace a fuel sender?<br /><br />I have an '89 Four Winns 285 Vista. Twin OMC Cobra 5.7l. Two independent 70 gallon fuel tanks. 1 fuel guage with a port/stb. switch. The guage works on the Stb. tank, but not the port tank. I'm assuming it's the sender because the guage obviously works.<br /><br />I just don't know anything about these senders, and what I need to replace it with.

 

[achris]

Re: Fuel Sender

You'll need to know the resistance range of the sender. Most are 33-240 ohms, but some are 0-90 ohms and some are different again. <br /><br />If it's not too hard, pull the working unit out, then measure it at full and at empty (float full up and float full down) with a multimeter.<br /><br />Chris............

 

[rybad]

Re: Fuel Sender

Other than the ohms measurement, are the sending units pretty generic?<br /><br />Thanks for reply.

 

[achris]

Re: Fuel Sender

Not really, some have a 6 screw pattern, some have a 5. And there are different diameters too.

 

[rybad]

Re: Fuel Sender

Thanks.. I will pull the bad one to match up.

 

[Boatin Bob]

Re: Fuel Sender

You might just want to quickly check the wiring by grounding out the sender wire, this should cause the guage to peg all the way over, if it does then it's pretty much the sender itself.

 

[rybad]

Re: Fuel Sender

Bob; I have two tanks, and a "switch" on the guage to select which tank to "read". The guage works accurately when I select Stb. It drops completely off when I select port. So, I'm sure the guage itself is working. I guess I should still trace the wires going to the port tank, instead of jumping into a sending unit problem. I'm just nurveous about playing with wires on a gas tank.. since I'm not fimiliar with them.. I don't want to blow up. At least not this early in the season!<br /><br />-Dave

 

[achris]

Re: Fuel Sender

Probably not the best idea to ground the sender wire. If the gauge is expecting to see 33 ohm at full, then when it sees 0 ohms it will peg alright, and probably bend the needle in the process.<br /><br />Chris..............

 

[cosander]

Re: Fuel Sender

my float isnt floating. Is there a place I can find another one? Or is it a regular piece of cork?

 

[Boatin Bob]

Re: Fuel Sender

David...I know your guage is working but my idea was to check the wiring from the faulty tank to the guage, all the sender is doing is acting like a variable resistor between ground and the guage, by grounding the sending wire momentarily the guage should peg, have done it many times and I know others have as well, this proves out the wiring all the way up to and including your switch right to the guage. It's just something thats very easy to do before you start pulling the sender out. The way I do it is to attach the sender wire to ground and then turn the key on to power the guage, there is no spark at the sender end and if you are nervous about it you can just use a jumper to some other ground thats no where near the tank.

 

[Ralph 123]

Re: Fuel Sender

achris, Teleflex recommends grounding the sender to check the gauges.<br /><br /> http://www.tflx.com/pdf/GAUWORK.pdf

 

[rybad]

Re: Fuel Sender

(Bob - Thanks.. I misunderstood your original post.. that makes sense.. I will try it.)<br /><br />Thanks everyone for the advice.