How do I replace fuel sender

[Sea Mitch]

I have a '93 Grady 232G Gulfstream with a '93 Yamaha 250 (250TXRR). Since the fuel gauge works when the switch is in the aux position, I'm assuming the main tank's fuel sender isn't working. (the gauge is always showing empty when in the main position) I have access to it but am a little reluctant to mess with it since it's on the gas tank! I'm pretty handy with cars, never had to deal with the boat till now. <br /><br />What am I in for? Is this a messy job? Can I do it with some gas still in the tank? Is it hard to reseal once removed? Any tricks or tips would be helpful. How do I find the correct replacement? Is this a job better left to a pro or can I probably do it? Are there books that are helpful, the boat manual is useless, all it has is a schematic and boating instructions? Whew, I'm loaded with questions!

 

[ThomWV]

Re: How do I replace fuel sender

Its really no big deal. Make sure the tank's not full. I have done it with mine with the tank a quarter empty, but I'd prefer it to be less than that. Anyway there will be 5 screws holding it in. Just disconnect all the wires and remove them from the area (in case one of them might be shorted to some other wire somewhere) then remove the sender and lift it out. You will probably have to twist it to one side to clear the float. The new sender will require that you adjust it for the height of your tank, so when you take the old one out just dip a measuring tape down into it to see how deep it is. There is a gasket with the new one of course, and you don't want to try to tighten the screws on the new on so tight they strip out, just tight enough will be OK. Don't use any sealer on the gasket for the sender either. After you hook up the wires, with new clean connectors on their ends too while you're at it, daub a little blob of dielectric grease on each electrical fitting after its all tightened up.<br /><br />By the way, most of the time its the guage, not the sender. Actually most of the time its the wires and connectors that corrode out from under it first, particularly on the negative side.<br /><br />Thom

 

[Kesh]

Re: How do I replace fuel sender

humm... just a question, my mechanic just re-installed the fuel sender of our Tai-Tai. He used some sealer because the gasket was old, and a bit "hardened". I guess it was ok to use the sealer. Any particular reason not to use it???

 

[Solittle]

Re: How do I replace fuel sender

I would use a light sealer. <br /><br />I did mine last year (23' CC - 122 gallon tank). I called the tank manufacturer (shown on the tank data plate - my data plate is right near the sender) & gave him the model of the tank. They sold me the sender calibrated to my tank model. I probably paid a couple of bucks more but feel more confidant in the accuracy of the reading.<br /><br />It is a pain free job but one I wouldn't tackle if I knew the tank was 100% full until it got down a bit.

 

[Sea Mitch]

Re: How do I replace fuel sender

Thanks guys! I'm printing this out as I type!<br /><br />Can I change the corroded wires and/or connectors without changing the sender? I could test for continuity and resistance but I'd have to splice the corroded wire unless I can "attach" it to the sender by cutting out the corroded portion. Does this sound right?

 

[Solittle]

Re: How do I replace fuel sender

Yep!

 

[ThomWV]

Re: How do I replace fuel sender

You can usually use the old wires to pull through the new wires. The usual way to check the wires is to simply cut off the connector on the end and then cut back a few inches of wire (make sure you have enough excess first) and see if you have the dreaded 'black wire' corrosion under the insulaton. Why not use a sealer? Because you will have to get that gasket off there some day. If a gasket is 'dried up' you could simply use good old general purpose grease as a sealer and won't cause problems, otherwise put it in dry. Oh, and here is how you can tell if there is too much gas in the tank to do the job. If there is too much fuel in the tank it will come squirting out of the hole when you remove the first screw. Really. The screw holes and the screws themselves go all the way into the tank, you pull one out and fuel follows if its filled to the level of the sender. Just a note too, these things are as generic as tooth brushes, just pick up one and stick it in, no reason to hunt the earth for the exact same make and model you took out. As I understand it there are only two resistance ranges used in their calibraton, and the vast majority of them use the range that Tempo does (something like 20~240 ohms as I recall).<br /><br />Thom

 

[Arnold96]

Re: How do I replace fuel sender

I had a similar problem. I just removed the wires and cleaned the connections and it now works. Adding a touch of electrical connection grease should keep it from happening again.