Sort of long, but this is a really simple fix for what may seem like a complicated problem at first. This short fix will possibly save you from lots of headaches and frustration if your wiper won't park.
I'm using a Lucas rotary wiper switch and the FFR-supplied wiper motor. Lots of good threads here on the subject and one of them resulted in a great wiring diagram for use with my switch. Unfortunately, the park function still didn't work. After double checking all the wiring, I figured it was a mechanical issue.
Sure enough, the spring loaded pin/post that activates the park switch was stuck in the "down" position, which results in the motor always thinking it's in the park position when the dash switch is turned off.
The switch is contained in the electrical connector on the outside of the motor - the opaque white plastic part. It's held to the motor by a single clip and is easily removed. It helps to have the motor out of the car. I took the backing plate off, then removed the two "C" clips that hold the round gear in place and popped that out of the housing. Using a flat blade screwdriver to lightly pry up on the clip holding the electrical connector in place, it popped right off.
Here's a stock picture I found on the web showing the park switch / electrical connector removed from the wiper motor - note the pin/post sticking up in the top of this picture. The point where the harness plugs into this when mounted on the motor is the the right. The spade terminals that are visible are those that connect to the wires going down into the lower motor housing:
The park switch operates very simply. When looking at the electrical connector on the motor, the lower right spade terminal is the one for 12v feed to the park function. The spade terminal directly above that is for the park switch. The round nylon gear that you removed (above paragraph) has a short ramp - 3/4" long or so - and when that passes over the spring loaded pin/post on the electrical connector, it pushes the pin/post down, which disconnects the power between the two spade terminals. So, when the dash switch is turned off, if the ramp is not pushing the pin/post down, there is an electrical connection that takes over between the park 12v and the park switch terminals, allowing the motor to make the rest of the rotation until that ramp pushes the pin/post down, cutting off the electricity.
Here's a pic of the nylon gear and ramp (called the "bridge" in this pic) that I found on the web... this is not my gear:
The problem with mine was very simple. I'm sure that the motor was tested at the factory, but according to the tag on the back of the unit, that was in 2008. When they tested it, it would have stopped at the park setting, with that pin/post pushed down. Well, after sitting like that for six years (nearly five of those on my shelf), it is no surprise that it stayed in that position when the motor turned during my tests. And, when I turned off he dash switch, it simply thought it was at park. I manipulated it a little and after a couple of pushes (it had a little spring loaded movement, but not much), it sprang fully out into the "on" position. I added a little dialectric grease to lubricate it and all now seems fine.
So, if your park function doesn't work, try this little trick to make sure that the pin/post is protruding about 3/8" out of the housing when removed from the car. Also, you can check continuity to make sure that you have contact when it's "out" and no continuity when pushed "in."
Finally, if there's no continuity between the two right side spade terminals, your motor is either actually parked or, like mine was, the switch is stuck in the "in" position.
I'm using a Lucas rotary wiper switch and the FFR-supplied wiper motor. Lots of good threads here on the subject and one of them resulted in a great wiring diagram for use with my switch. Unfortunately, the park function still didn't work. After double checking all the wiring, I figured it was a mechanical issue.
Sure enough, the spring loaded pin/post that activates the park switch was stuck in the "down" position, which results in the motor always thinking it's in the park position when the dash switch is turned off.
The switch is contained in the electrical connector on the outside of the motor - the opaque white plastic part. It's held to the motor by a single clip and is easily removed. It helps to have the motor out of the car. I took the backing plate off, then removed the two "C" clips that hold the round gear in place and popped that out of the housing. Using a flat blade screwdriver to lightly pry up on the clip holding the electrical connector in place, it popped right off.
Here's a stock picture I found on the web showing the park switch / electrical connector removed from the wiper motor - note the pin/post sticking up in the top of this picture. The point where the harness plugs into this when mounted on the motor is the the right. The spade terminals that are visible are those that connect to the wires going down into the lower motor housing:
The park switch operates very simply. When looking at the electrical connector on the motor, the lower right spade terminal is the one for 12v feed to the park function. The spade terminal directly above that is for the park switch. The round nylon gear that you removed (above paragraph) has a short ramp - 3/4" long or so - and when that passes over the spring loaded pin/post on the electrical connector, it pushes the pin/post down, which disconnects the power between the two spade terminals. So, when the dash switch is turned off, if the ramp is not pushing the pin/post down, there is an electrical connection that takes over between the park 12v and the park switch terminals, allowing the motor to make the rest of the rotation until that ramp pushes the pin/post down, cutting off the electricity.
Here's a pic of the nylon gear and ramp (called the "bridge" in this pic) that I found on the web... this is not my gear:
The problem with mine was very simple. I'm sure that the motor was tested at the factory, but according to the tag on the back of the unit, that was in 2008. When they tested it, it would have stopped at the park setting, with that pin/post pushed down. Well, after sitting like that for six years (nearly five of those on my shelf), it is no surprise that it stayed in that position when the motor turned during my tests. And, when I turned off he dash switch, it simply thought it was at park. I manipulated it a little and after a couple of pushes (it had a little spring loaded movement, but not much), it sprang fully out into the "on" position. I added a little dialectric grease to lubricate it and all now seems fine.
So, if your park function doesn't work, try this little trick to make sure that the pin/post is protruding about 3/8" out of the housing when removed from the car. Also, you can check continuity to make sure that you have contact when it's "out" and no continuity when pushed "in."
Finally, if there's no continuity between the two right side spade terminals, your motor is either actually parked or, like mine was, the switch is stuck in the "in" position.
