Intermittent wiper not working Options

[michaelmoo]

Ok I have the intermittent relay and a washer pump on my car. First ever thing is wired correctly and making good contact. Second, I know the order of the wiper switch: all the way down is intermittent, then off, then slow, then fast (well faster than slow…). Pulling the switch you get like 4 or 7 swipes and the pump comes on. That is how it is suppose to work.

Here is what I get: all the way down is nothing, then off, then slow, then fast (well faster than slow…). Pulling the switch I get the 4 or 7 swipes and the pump comes on.

Thoughts? If the relay was bad would the 4 or 7 swipes still happen with the pump?

Mike

[Bartlett 914]

You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.

[markb]

You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.

I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why. (IMG:style_emoticons/default/dry.gif)

[Bartlett 914]

You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.

I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why. (IMG:style_emoticons/default/dry.gif)

I have done a lot of work on this project. The intermittent relay has 3 modes. Off, on for several seconds and on for 1 second switching off for about 5 seconds.

The first is obvious. We need to turn off the wipers. The control wire is the brown with a black stripe. In the off position it is held at ground. This connection is the one from the mounting screw that holds in the wiper switch.

Moving to the intermittent position (full down) this connection is open. In this position the connection must be greater than 15K ohms. In this position, the relay has the on for a second and off for 5 or so seconds. When it switches on for a second, the wipers move out of the park position. They continue until they are again parked and wait for the next pulse from the intermittent relay. Because the control wire is open for this mode, if the screw is not tightly holding in the wiper switch, we can get ghost wipes.

The third position is +12 volts when pulling back on the wiper switch. Pulling back opens the valve for washer solvent flow and applies +12 to the intermittent relay. The relay will hold as long the 12 volts is applied and the wipers will operate continuous. When the 12 volts is removed, the relay will hold for a few seconds longer running the wipers for several additional sweeps.

Because the intermittent mode uses an open condition and if we install a washer pump, the resistance of the washer motor acts as a ground. Therefore the intermittent mode will not work. The open must be greater than 15k and a washer pump is around 50 ohms.

I was just able to make both modes work on my car. I installed a circuit card that has a relay, 2 transistors and 3 resistors. The input impedance for this circuit is greater than 27 K ohms. This allows all functions to work.