ok i just picked up another 97 civic and i didnt know at the time the gass needle didnt work. so i check the float and it seems good. i unplugged connector b on the cluster and it didnt do anything. i also checked the motor on the cluster and all the wires seemed to be connected and not broke off. so then i moved the needle all the way to E then turned to the on position and it went all the way back up the just a lil bit past the full mark. so i was if this is the cluster or the sending unit?

 

check sensor in tank

 

i took the sensor/float out and the float seemed fine. is there a visual way to tell if the sensor is bad?

 

the gas gauge works off of a float in the fuel tank that is attached to a variable resistor on the sending unit. At a full tank the resistance is very low. as the float drops the resistance increases and the indicated amount of fuel on the gauge drops.

if you have a fuel gauge the reads full all the time either the float is stuck (unlikely) or the sending unit is shorted out. its quite possible that in the cold weather the two pieces of metal that are shorting out are separated because the metal contracts; in the hot weather the metal expands and the two pieces contact each other and create the short circuit.

I expect that you will have to replace the fuel tank sending unit to fix this problem

 

I would first just pay the money for a new sending unit. I paid 25$ for mine. Not sure if my dad ever put it in his car or not but i know it never fixed the problem. Idk if you have the same problem as myself but i need a whole new cluster. But change your sending unit before you change your cluster.

 

 

FYI, these symptoms are also a sign of a bad gauge unit in the cluster. I've seen this happen on clusters where someone removes the fuel/temp gauge, then on reinstallation overtighten the screws that fasten the unit to the PCB, and wreck the little wire contacts on the gauge below. (Ask me how I know. ) It's possible to fix with a steady hand and a soldering iron, though. In fact, this problem is common enough to warn people about in the FAQs and should have a link to a DIY repair (which a rough one exists, as I recall).

 

i went a bought a multimeter today not exactly sure how to use it. but hopefully i can figure it out and check the sensor tomorrow and the float