Windscreen Wiper Timer

The picture below shows the INT TIME feature that allows the user adjust the time interval a wiper should clean the windscreen while in timered position.

(click on the pictures to enlarge)

Unfortunately, my car don´t have this feature. It has the timered option but for a single fixed time interval of around 5secs. I love this feature so I decided to add it to my car by my own. Below a picture of the original relay that generates the pulses in regular intervals for the wiper motor.

Inside it, details of the main board and its components.

I removed all the components from the original board. Only the relay remained. Then, I made a PIC based litte board and attached it to the main board.

To adjust the time interval, a Up and Down board was developed. This one is supposed to be under the car´s panel on a hidden but accessible location..

Due to the lack of documentation, I had to discover voltage levels and pinout operation by myself. Below is the pinout description of the relay.

15 - This pin receives 12V when the car key is turned on.

31 - GND.

53M - Output to wiper motor (when VCC, motor is running).

53S - A pulse that returns from the motor to indicate the wiper reached the idle position on the Windscreen.

T - This pin receives 12V when the windscreen washer is fired.

I - This pin receives 12V when the windscrees wiper is turned on and set to the timered position.

Use is simple. It is a matter of turn on the windscreen wiper in the desired speed. Int Time / Normal / Fast.

By selecting the Int Time option, interval may be adjusted by pressing the Up and Down buttons.