i just changed my fuel filter on my truck and when i got back in it and started it up my wif light come on and have no clue why? it wasent on before

 

Did you disrupt the wiring for the sensor, mine connector came off once and I had the light

 

Also, you need to clean the terminal tips inside the canister. Just wipe them off.

 

If you don't clean the terminals as Jerry said often crud from removing the filter falls down and shorts across the sensor.
It doesn't take more than a hair to make the light come on.

 

In the many fuel filter changes Ive done, Ive had many times when the WIF light was on post filter replacement. In all but two cases, doing the basic cleaning mentioned above corrected the issue. However, in those other two instances, it turned out I had two bad filter canisters.
In both cases, replacement of the fuel filter canister was done which rectified the WIF light issue.

 

yea i did disrupt the wiring from the sensor, i will try to clean the terminals and see if that does it