Windshield Wipers on '90 F150 Custom EC
Since buying this pickup, I've been a bit torqued that it has only 2-speed windshield wipers: slow and constant, and fast and constant. Because interval wipers have been on vehicles since well before 1990, I wondered why there were none on this, admittedly very basic, vehicle.
A few days ago I was cleaning out the dash pocket and came across the owner's manual. Out of curiosity, I looked at what it had to say about using the wipers. I was surprised to learn that it described 3-speed washers and had no mention of this being anything other than standard OEM stuff. On reading the details, it said that turning the switch clockwise would offer first low-speed constant wipers and turned one notch more would give hi-speed constant wipers. Yep! That is how it works. Reading further, it instructed me to push the switch toward the dash to activate the washers which would automatically start low-speed constant wipers. Right again! It works exactly that way. Then came the surprise. The manual says that turning the switch one step counter-clockwise would activate the low-speed, delayed interval wipers that I was looking for; however, the switch in my ride has no such counter clockwise action. I tried turning counter clockwise without pressing the switch without success. I would not turn. I then tried pressing toward the dash and turning CC but it only started the washers and constant low-speed wipers. Pulling on the switch had no effect other than the know coming off in my hand.
So, here is my question: Is there any way to determine if the wiper motor is actually a 3-speed? If it is, can I buy a switch that will activate interval wipers at low speed? If not, why does the manual contain the instructions that it does?
While I am the second owner of this vehicle, I have no evidence that the washer motor and switch are anything other than original equipment (although I suppose it is possible that they were replaced).
Can anyone shed any light on this?