This has been a topic of discussion many times on this and other sites so I want to share my technique for calibrating a new sender unit.
The factory had a set amount of resistance in their senders that worked with the size of the tank and the gauge on the dash but once you install an aftermarket or even OEM sender your gauge may not read the actual fuel level in the tank,this is caused by variations in the resistor or position of the height of the sender. The time to correct this is while installing the new sender and/or pump.
I'm not going to get into how to gain access to your sender because of all the different configurations.
Once you get the old sender out measure from the bottom of the tank to the opening in the top of the tank,that will be your reference measurement and half of that measurement is half tank.
Disconnect your fuel pump relay(if applicable)and make sure your new sender is grounded and plugged into the harness then set the float to your half tank position as measured down from the mounting flange. Turn the key on and verify that the gauge reads half tank. If the gauge reads low bend the float arm down,reset the float height to the half tank measurement and recheck. Bend the arm up if the gauge reads high.
Some tanks have a raised area where the sender goes into the tank which raises the sender in the tank. This works out in your favor by giving you a reserve when the gauge reads empty.
The factory had a set amount of resistance in their senders that worked with the size of the tank and the gauge on the dash but once you install an aftermarket or even OEM sender your gauge may not read the actual fuel level in the tank,this is caused by variations in the resistor or position of the height of the sender. The time to correct this is while installing the new sender and/or pump.
I'm not going to get into how to gain access to your sender because of all the different configurations.
Once you get the old sender out measure from the bottom of the tank to the opening in the top of the tank,that will be your reference measurement and half of that measurement is half tank.
Disconnect your fuel pump relay(if applicable)and make sure your new sender is grounded and plugged into the harness then set the float to your half tank position as measured down from the mounting flange. Turn the key on and verify that the gauge reads half tank. If the gauge reads low bend the float arm down,reset the float height to the half tank measurement and recheck. Bend the arm up if the gauge reads high.
Some tanks have a raised area where the sender goes into the tank which raises the sender in the tank. This works out in your favor by giving you a reserve when the gauge reads empty.
