f-600 gas guage troubles

[1lowf150]

i am running a f-600 guage cluster in my truck, and everything was going ok till one day the needle for the gas guage stopped working. i have aftermarket guages under the dash for oil psi and temp so the only thing i hooked up in the cluster was the fuel guage and the speedo. i have a 25 gallon 78 bronco gas tank with the wrong sending unit. i ordered a 33 gal sending unit for what i thought was a 33 gal tank that had been in storage in the garage for a few years. i had to bend the float on it to even go in the 25 gal tank, so the needle was always past the full mark when i would fill the tank,well after driving the truck for about three months one day the needle was gone. the needle is clear down past the empty mark almost outta sight. i am planning to get the correct sending unit but do not have the budget to replace all the guages right now. anyone have any ideas what might be wrong? any help would be great.

[fordman]

its probably going to test out just like our guages would on the fuel diagnotics page. i would try that.
http://www.fordification.com/fuel-sending-units.htm

[1lowf150]

thanks fordman i will check it out.