Packard Forum Index » Modification Discussion

Since one of my Fuel Senders got eaten up by rust. I went in search of an replacement. I liked the sender that Howard (HH56) made, see:
packardinfo.com/xoops/html/modules/newbb ... at&order=ASC&type=&mode=0&start=240

But I was looking for something a little more plug and play as we say at work. So I tried a couple and made a video if anybody would like to try it themselves.
I went with the 16 - 158 35 - 240 ohm sender and it looks like it will work out pretty good. All that is needed it a little filing and adding a resistor to get the gas gauge calibrated to Empty.
Watch and tell me what you think.

youtube.com/watch?v=6UDLFoF2Evo
Wes
P.S. Sorry about that 35 to 240 ohms.

Very good. I like your approach and it may be the simplest solution and definitely cheaper than having KM Lifestyle make a sender in the old S-W range. Believe the 35-240 is the new S-W range and has become more or less a universal or aftermarket standard. There is one 0-100 ohm modern sender I found that MIGHT be able to be made to work but it seems to only be available in Australia. Their website shipping calculator didn't work for me to find an amount to ship to US but expect it is probably more than the sender. No specs as to which end is the 0 ohm side.s3performance.com.au/acewell-100-ohm-fuel-sender/ACE-TS

To carry your experiment farther, I wonder if the resistor in the 16-158 sender is linear.. If so, could the arm be longer and bent or else a sleeve or collar made to slip over the original arm mounting method to change the wire location. Make it so when float hits the top of tank sender is at 0 ohms. Use extra length on the wire to extend the float so it won't use the entire range of the resistor -- say have it long enough it hits the tank bottom at 100 rather than the 158. That would be roughly 3/5 or 2/3 of the travel allowed. That is what I did with the pot I used -- It was a 400+ ohm linear pot but I am only using something like 1/4 of the range.

While you still have your mockup in place would you test and guesstimate an idea of how long the wire would need to be so it stops at 100 and if the longer wire would fit in the tank?

If that approach doesn't work out, publishing your final ohm value on the 240 sender and the particulars of how the wire was sized and bent should help several out.

Here's a couple of pictures on modifing the sender, I first opened it up and removed the wirings as one whole piece. ( It looks like you could almost rewind it for 100 ohms but I didn't want to go that far.) Next I took a small round file and filed a grove where the arm would lay. Then I put the winding back in and checked that the wiper on the arm touched the very end for zero ohms.
I will make more checks later.
Wes
P.S. I should have taken a before picture, the first picture was after the filing.

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One more post for the day and then it's goodnight.
Wes

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Wes, what is your trade? i see many computers and your setup board is impressive! this was interesting as i don't think my sending unit is functioning correctly on my 37. it reads 1/4 tank even when i fill it up. another project for my blog at some point.

I work for a major overnight (as we say "Fly By Night") shipping company. Maintain the Flight Simulators and I was farm raised where anything can be fixed and hard work never hurt anyone.
Wes

Okay to follow up on Howards question, first I meant to say I'm going to use the 35 - 240 since the windings work better not the 16 - 158. Second I did look at yours and I was thinking that with a 350 ohm pot I could adjust the arm length and get my 0 - 100 ohms, but as I said I'm looking for something that is off the shelf. Third I was thinking that I could adjust the arm for a 0 - 100 ohm swing with the 35- 240 ohm unit. But I had already cut the arm and bent it for the float. The next one I will try using the arm to get the 0 - 100 ohm swing without a resistor added in parallel.

I have run into one problem, if you break the circuit ( wire comes off or you disconnect the power) then Empty does not read correct. This has something to do with the gauge. It also happened with the Packard Sending Unit. The needle will go way pass Empty ( Needle on left hand side of the Dot). but once you drive the gauge back up then Empty reads correct. So I'm looking into running some test and see what happens.

Now if you look at the pictures you will see the arm is almost 4 inches long with a slight bend so it can touch the top of the inside of the tank.
The resistor I use was a Red Violet Brown 270 ohm using that with the 240 ohm Fuel sender comes out to be 127.059 ohms when I put my meter on it it read 130 ohms, close enough.

I know we were looking for 0 - 100 ohms but with the testing 130 looks like it works better. More testing to come.

So just to recap 270 ohm resistor, 4 inch arm and this is for a 17 gallon tank.

P.S. If anybody would like some slightly use fuel senders, let me know. I can't guarantee them, the cost of playing around.

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Here is a schematic of the gauge and sender as a unit. Basically what happens is with the wire to the resistance unit open there is no current flow thru the series coil. With nothing to balance the pull of the potential coil, the needle is moved off scale past the working range.

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Today I ran a test and it didn't look to bad. My biggest problem was the Whistle pipe must be plugged. After the first five gallons, I had a hard time putting the final 12 gallons in. Did a bleed down and it didn't look to bad. But I need to fix the tank before I go any farther. Just order another fuel sender, the 35 - 240, this time I will see if I can adjust the length to get my full movement from Full to Empty.
So wish me luck.
Wes

Well I had to fix my Ventalarm before I could checkout my off the shelf sender. So here's the final out come. I probably could have gotten the gauge to read closer to Full but I am more worried about here the tank reaches Empty. This is for a 17 Gallon Tank, when and if I get my other tank fix then I might do a video for the bigger tank. For now I'm holding out to this tank until I get the bigger one fix or I give up on it.
So here's the video:youtube.com/watch?v=LQqh9ayQRWA
Enjoy!
Wes