When I bought my Centech harness two years ago, I discovered that they supplied a wiper switch that was completely different than the one in my Bronco. Besides being different, it didn't interchange mechanically or electrically with the stock switch. It required modifying the hole in the dash, modifying the wiper motor and it didn't have a connector on the back of the switch- just individual wires with spade connectors. I already had an intermittent wiper switch from a Ford F150 pickup, and I didn't want to give it up. So I figured out how to modify the new harness to accept my intermittent switch. Since then, I've had several requests from others on how to do this modification. Here's what I learned, and how to do it 1. You will need the stock Ford wiper switch electrical connector from your old harness to do this mod. Cut it off with about 3 inches of wire, to make electrical hookup easier. If you don't have the connector anymore, you'll need to get one from a junkyard donor. The following photo shows a picture of an OEM Ford wiper switch connector: Ford used the same connector on a zillion vehicles from the mid 60's through the 80's. In the late 70's some vehicles (F150's and Broncos) came with a two-piece connector. I recommend avoiding those. They will work but are clumsy to connect. 2. DO NOT MAKE THE MODIFICATION TO YOUR WIPER MOTOR THAT CENTECH DESCRIBES IN THEIR INSTRUCTIONS! The "Motor Stop" circuit is required in order for the intermittent switch to function. 3. The Centech harness is missing a wire required to use the Ford switch (for the Motor Stop circuit), which you need to add in order for this to work. I just used a length of black 18 gage wire (same color as the Ford wire that Centech eliminated) and routed it along the harness from where the wiper connector is located, over to the rest of the wires going to the wiper motor. I used electrical tape to hold it to the harness. Note that this wire does NOT serve the same function as the black ground wire that's already in the Centech harness. It's there in case you are using a fiberglass body, to ground the motor case. DO NOT connect the Centech ground wire to the "Motor Stop" wire. 4. Ford made their wiper switches, and the corresponding electrical harnesses in two flavors. The older ones had seven wires going into the electrical connector. The later ones (after about 1979) had six. However, they all used the same plastic shell for the connector. The late models just an empty slot where the older ones had the seventh wire. The difference was in how the washer motor was powered. The extra wire came from the fuse panel and was used to supply power for the washer motor function. Ford added a jumper inside the wiper switch on the later models so that the washer circuit could be powered from the same source as the wipers. Simplified things and probably saved a little money. The intermittent switch assemblies thus also had 6 or 7 wires respectively, depending on the year of the vehicle. The seven wire switches are less common. A six wire switch can be made to work with a seven wire connector (what all early Broncos had). Determine which style you have, then follow the rest of the directions accordingly. 5. Note that even among early Broncos the wire colors changed over the years, I'm not going to refer to any Ford wire colors in the directions below. 6. For reliability, I recommend soldering each connection and applying heat shrink tubing. Much more robust than crimp splices and/or electrical tape. 7. Now the nitty-gritty connection details. The following photo shows a picture of the harness connector, taken of the face that mates with the wiper plug, with each terminal numbered. Use the table appropriate to the intermittent switch you have. Cut the spade connectors off your Centech harness at the wiper switch, then follow the numbering in the table to make the new connections.   IF YOU HAVE A 6-WIRE INTERMITTENT SWITCH: Wire Number: Corresponding Centech wire, by color & function: 1 Green (park power) 2 Orange (+12 volt supply from fuse panel) 3 Not used 4 Purple (washer motor) 5 Blue (high speed) 6 *Added wire* (motor stop) 7 Yellow (low speed)   IF YOU HAVE A 7-WIRE INTERMITTENT SWITCH: Wire Number: Corresponding Centech wire, by color & function: 1 Green (park power) 2 Orange (+12 volt supply from fuse panel) 3 Purple (washer motor) 4 Jumper this wire to no 2 (Orange wire) 5 Blue (high speed) 6 *Added wire* (motor stop) 7 Yellow (low speed) If you do the hookup for a 7 wire intermittent switch and later want to use a 6 wire switch, do this: cut the jumper from terminal 4 to terminal 2. Use a jewelers screwdriver to pop the now-disconnected spade connector out of the terminal 4 hole. Pop the purple wire out of the terminal 3 hole and move it to the terminal 4 hole. The terminal 3 hole remains empty. That's it, connect the 6 wire intermittent switch- the washer function works the same as the older switches. 8. Now you can make the connections from the Centech harness to your wiper motor, except of course you will ignore their admonition to not make the Motor Stop connection. For the record, I never had the fuse-blowing problem with my wipers as described by Centech, either with my stock wiper switch or with the intermittent switch, when I still had the stock Bronco harness, and still don't. Once you have made all the connections, plug in your switch and enjoy having intermittent wipers! Tech article by Lars Pedersen (Lars)