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Not that strange Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 1 May 2006 10:27:56
In Reply to: Windshield washers, Mike G., Mon, 1 May 2006 09:52:32 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The washer motor gets its 12 volts directly from a set of switch contacts in the stalk. The motor is an inductive load, which means that when the switch is released, it drives a high-voltage spike back through the switch contacts as they open. This makes a small burn mark with carbon buildup. Over time the switch contacts get pitted and dirty with carbon, which is a lousy conductor. I'll bet that if you were to put a voltmeter on the connector to the pump with the pump DISCONNECTED, you'd see a nice 12 volts there when you pull the switch. Connect up the pump and look at the same pins, and you'd see maybe a couple of volts.
That's because with the meter alone (no pump), you're reading volts through the resistance. The meter doesn't pull any load. But with the pump connected, there is a voltage drop across the dirty switch. Why does it work sometimes? Because there is just not quite enough current flow to turn the motor. But sometimes there is - maybe its vibration, or just whatever. But the starting current is much higher than the running current - once the motor turns, the current draw drops and the motor spins.
You've got two choices - you can either replace the switch assembly or repair it. At a minimum, you can try opening up the surround to access the switch, and trying to spray into the switch with some electrical contact cleaner. Give it 10-15 minutes to dry, and see if that helps. If not, you can try opening up the switch and cleaning the contacts with a little fine sandpaper. Be careful; the switch contains little levers and springs. And if you really blow it and parts fly to 3 out of four corners of the room, you can always go to Plan A, and buy a new one.
posted by 192.249....
, Mon, 1 May 2006 10:27:56 <-- Viewing This Message
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