My 65 coupe didn’t have a windshield washer. So after I got it out of restoration I installed a pump, bag and all the right stuff. Now I’ve discovered that the switch that came with the car is not the washer type switch. My question is if I get a washer type switch will I have to get a different wiring harness. The plug now is a 5 prong plug that plugs onto a 5 prong switch. Can I tie into the existing wiring harness somewhere?