Gas guage stuck

[redwing]

Just discovered that my gas guage on my '78 Crestliner is stuck at reading slightly over half full with a full tank. I grabbed my volt meter and I have 12V on the guage terminals but does that necessarily mean it's getting a good signal from the sender? Anyone know a good way to isolate the problem to guage and/or sender?

 

[OBJ]

Re: Gas guage stuck

Hi ya' redwing....<br /><br />I'll try to help some. The signal yer interested in is the one coming from the sender in the tank. A reostat in the sending unit changes resistance as the float changes level with the gas. This resistance change causes a voltage drop across the reostat and changes the amperage to the coil in the gage. Read the voltage drop across the gage post marked signal. You may want to pull the sender out of the tank and work it by hand as you view the meter. If the sending unit is as old as the boat, it may be the cause. Hope I've helped out some.

 

[Boatist]

Re: Gas guage stuck

Redwing<br />Does the guage stay the same with the Key OFF or does it drop to empty?? If it stays the same place with the key off I bet it is the guage. You can pull the wire off your sending unit at the tank and guage should read full or empty then ground to the ground wire and should read go the other way. Always check for loose connections or corrosion at all connections.