I recently purchased a 10ae that needed a new chassis harness. It came with an s5 gxl set up that's in perfect condition but I'm not sure if I can use it and run the stock switches fir the 10ae. The switches are series 4 and I'm not sure they will work with the s5 harness and if it does my worry is the washer button for the headlights might not work.

How do I find out before assembly or how would I modify to assure its functional?