What is the deal with the changing of the fuel pump wiring harness? I have an 03 Flex fuel 5.3L and I bought the AC Delco OE pump assembly and it appears to have the orignal style wiring harness. From reading the posts, the harness needs to be replaced. I am confused what do I replace when I have the OE pump. It seems some of the aftermarket pumps have the new wiring harness for both the pump and the engine side of the connector. I don't want to do this job again and would like to do it right the first time. Any recommendations?

 

They changed the connector on the pump, if yours plugs into your new pump you do not have to change it.