gas gauge issues

[brentleedragon]

So any how I just hooked up my rear tank put a new sending unit in, took it down dropped some gas in it (enough to put it to the 1/2 way mark) I switch to the rear tank and it goes to a quarter tank..... I switched to my front tank and it goes to where it is, but when I switch to my rear tank it just stays at a 1/4 even though it should be at half.

I sanded everythjingd own grounded it, I cleaned the pig tails and everything


possible electrical issue upfront?

 

[UNRULEE]

Maybe the float has a hole in it????

 

[Mil1ion]

Time to do some resistance tests on that SU


They are calibrated to read empty or zero at 70 Ohms of resistance. The full or maximum reading will be at 10 Ohms. All of the senders are calibrated for this 70-10 Ohm range. The fuel sender at 1/2 tank should read 40 Ohms.

~Ohms >> Reading
150 >> No movement - same as if the wire were broken or disconnected
73 >> Off scale 1/2 needle width below E
68 >> E
50 >> 1/8
26 >> 1/2
15 >> 7/8
12 >> F
10 >> Off scale a needle's width above F

 

[brentleedragon]

I tested the resistance before putting it in, and it tested out fine, everything was good. The gauge moves but it's such that a 1/4 is more of a half tank ? thats where my gauge should be now. The tank is sending fuel I have a clear filter on it so I can see and it is fine, I ran 30 miles on the tank no problems just no gauge but the resistance was fine, unless something in between me putting it in and installing the tank went wrong? (it was a new SU too)

 

[radialarm]

You could have bent the arm!!!

I doubt any two sending units read exactly the same!!!

Mine don't the rear will go about 45 miles after it hits "E", and you better be ready to switch the front when it gets to "E"!!!

 

[brentleedragon]

Yeah that's not what is happening though. At 10 gallons im barely at a 1/4 tank, thats a bit different than the E with 45 miles and the E truly meaning empty

before i replaced the tank and sending unit, my rear tank, empty meant empty

my front tank i get about 60 miles on E

 

[money_pit]

How many gallons did you put in it ? Was it empty ?