Windshield Wiper w/three wires?

[Searun1]

Help! I have just rewired my boat and have taken the time to do everything correctly with marine grade components. This has been needed since I purchased the boat. I have completed everything as of today and it all works.<br /><br />However... The windshield wiper motor has three wires. I know one must be the positive wire and I know which is the ground. My question is what would the third wire be for? The previous installation had the ground going to the ground on the bus bar. Then the other two wires went to the pull switch on the dash. I am running them through a switch panel now. What do I do? Why would there be three wires when only two are needed?<br /><br />Thanks for your help in advance.<br /><br />SeaRun1

 

[willamettejeff]

Re: Windshield Wiper w/three wires?

The third wire selects whether you want the wiper to go to its parked position after you turn off the wiper switch. I believe you would connect it to a 12vdc source that is still present after the wiper switch is turned off to have the wiper park itself. Not sure on that part though, but shouldn't hurt to try it.

 

[Boatin Bob]

Re: Windshield Wiper w/three wires?

I think William has it right. Mine have 3 wires also, in order for the self park to work there still has to power to the wiper for the motor to get to the park spot. So I believe one wire is ground, one wire comes from your wiper switch and the other wire from a 12 volt source. If you choose to only use the 2 wires and it is a self parking wiper then it will stop wherever you turn the switch off, could be in the middle of the windshield.

 

[AndyL]

Re: Windshield Wiper w/three wires?

I reckon that is right. If you open the motor case up you should notice that the third wire goes to a little microswitch activated by a cam lobe on the motor drive spindle. When you switch the power off the microswitch causes the motor to keep running until the cam makes the park circuit break. Hence the wiper arm always stops in the same parked position.

 

[Searun1]

Re: Windshield Wiper w/three wires?

Thanks guys! I also talked to the mechanic at one of the local marine shops and he told me the same thing. Heading out right now to finally finish the job. Have a good one.<br /><br />SeaRun1

 

[Perfidiajoe]

Re: Windshield Wiper w/three wires?

Make sure it only has 12 volts when the ignition is on, or you might develop a electrolsis problem. Good Luck, Joe