Fuel Tank Sending unit conversion.

[Softbuster]

Well last week I took the Fuel tank off of my Eagle wagon, it had a pin-hole leak from rust and the fuel gauge was not working properly.  So I decided to try to repair this.   I took the sending unit apart and found that the contacts inside were messed up, the only time the gauge would read anything was when the tank was completely full, anything less and it would show empty.
So I started looking for a sending unit, but the only ones available are over $100. which is not in my budget for this car.  So I did some research, our eagle sending units read in an ohm range of like 30-248.  Ford uses an ohm range of like 33-240, which would be close enough to work if you can find one that would fit our tanks.

Then I found a sending unit for a universal application in that 33-240 ohm reading, that is able to work with tanks from like 5" to 27" deep.
Its a Sunpro sending unit, part # SUN-CP7583   
which cost me 14.95 +sh from Summit racing , but it could also be found at other places like Jegs racing.

Then I proceeded to modify it to fit onto my old sending unit bracket.

Here is the two side by side.


The new sending unit comes with a diagram to figure out your depth and length of the float arm and stuff.
Pic of the new unit modified to length.


Then I gutted the old sending unit and disassembled the new unit.



Then I mounted the new unit onto the old bracket, I had to drill the hole bigger to fit the new rubber bushing that keeps the sending unit post from grounding to the bracket.  Do this very carefully, you don't want to drill it to big or ruin the old bracket.  You also have to make sure that the float arm does not hit the fuel pickup tube.



throughout this process be Very careful not to ruin the sock on the pickup tube IF you are going to reuse it.

I will hook up the wires and test the unit later this week, it will probably be a while until I get the tank back on the car, I am sandblasting it and fixing a bunch of small pinholes from rust.
But when its done I will let you know how it works and how accurate I think it is.
but in THEORY this should work.

Keith.

[IowaEagle]

Keep us up to date on this EGGcellent retrofit.  Once you are done I would like to put it in the AMC Eaglepedia.  Your conversion should be of particular interest to SX/4 and Kammback owners.

[thereverendbill]

stoystown auto recyclers offers NEW tanks for our eagles at right around 100 bucks if your interested send me a message and I'll give you their contact info

[IowaEagle]

Are these the 22 gallon 30 series or the 21 gallon 50 series tanks Bill?

[shaggimo]

Interesting indeed! Good tips!

[mramc]

Did you think about looking at a Jeep CJ gas tank sender? They look pretty close just looking at them on the internet and run about $53 on the net. LRDaum

[eaglefreek]

I used the same sender for my IH Metro. It worked great.

[Draekon]

I believe the resistance is the reverse on that universal gauge.  It reads 33 full while eagles read 30 when empty.  It'll work, just read empty when full and full when empty.
Correct me if I'm wrong though

[eaglefreek]

I believe the resistance is the reverse on that universal gauge.  It reads 33 full while eagles read 30 when empty.  It'll work, just read empty when full and full when empty.
Correct me if I'm wrong though

You sure about that? I've never measured one but the info I find while searching says 31 full, 248 empty.

[Softbuster]

Then I would have to reverse the wires at the fuel sender, which might work as long as it does not get a ground through the fuel tank 

[Draekon]

I believe the resistance is the reverse on that universal gauge.  It reads 33 full while eagles read 30 when empty.  It'll work, just read empty when full and full when empty.
Correct me if I'm wrong though

You sure about that? I've never measured one but the info I find while searching says 31 full, 248 empty.

I'm not sure.  I've just read that eagles and Jeeps are opposite, and from some brief research it looked like the one he ordered is the same direction as Jeeps.

[shaggimo]

That depends on the jeep too, some jeeps are opposite of one another. For example, my 87 cherokee had a sender from a 94ish cherokeee in it, the fuel gauge ran backwards, lol.
Even if the replacement did run backwards, I would think one could take it back apart, invert the potentiometer, and rebend the float pole, to trick it into running correct for the eagle....(if that makes sense, lol).

[Softbuster]

I did get a chance yesterday to hook up the wires to test the sender, and it worked fine.
when the float was down it showed empty, and when the float was up it showed full.
Did not have to reverse the wires or change anything.

Now the only question is, how accurate is it when there is fuel in the tank.

it will be a while until I get the tank back on the car, still have fixing to do and not much time to do it.

Keith.

[68AMXGOPAC]

Hmmm, I would think it as simple ( not meant sarcastically ) , as measuring the depth of the tank where the sender drops in and moving it up in measurable incriments based on the tank depth.  say - 12" drop - 3" up should be close to a 1/4 , etc etc ., hey as long as empty is empty , that would be my most worry.

[thereverendbill]

Are these the 22 gallon 30 series or the 21 gallon 50 series tanks Bill?

22 gallon, i will have to check and see if they offer the 50 series tanks