My windshield wipers do not work!!! how do you know if it is the motor or the switch they went on and off 3 times before it completely quit on me. first time they where out for a week and then 5 or so months later another week then a few months later now there broke and wont come back. the only setting that ever worked on them was the high setting and the others would would work every now and then. I have a ford ranger and the switch is connected to my blinkers and high beems which work fine
switch is cheaper and the part that wears the most.
The system is more complicated than it needs to be. I guess this is one of those better ideas. Power is controlled to the circuit through relays which are switched on by something called a Smart Juction Box (SJB). It is the fuse panel, but it has electronic computer circuitry built in. Why? Who knows, but that is the way somebody at Ford decided to make it. Anyway ground comes out of the SBJ to the coil side of the wiper relays (there are 2 of them) in the BJB-Battery juction box. The power side of the coils are fed by the ignition switch-on circuit. When the SJB decides to turn on the wiper relays, it provides a ground to the BJB relays which have power on the other side of the coil windings whenever the key is on. You decide what you want the wipers to do, by turning on the switch. The switch sends a resistance signal to the SJB, which in turn, makes that happen by turning on the appropriate combination of relays. There is a high speed relay and a low speed relay. Intermittant speeds are created by having the SJB time the switching on and off of the relays. So now you know, that you have a switch, SJB, BJB, two relays (plus a third for washer operation), a fuse (Do not know the year for your Ranger # in the SJB), the wiper motor itself, and all the wiring. A problem anywhere at all in that system can cause a wiper to not function. Hope it help
run a wire from the battery to the wiper motor (by passing the switch) if the wipers work like crazy, then you know the trouble is in the switch or in the power getting to the switch (may be a blown fuse) . From experience, and your description, I believe the switch will be the problem. If it is , you can run a 'hot ' wire from the ignition switch to a toggle switch ,to a fuse , to the wipers, and keep on trucking.
