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MG MGB Technical - Wipers dont self park

When I switch off the wipers they just stop dead.
Anyone know whats wrong?
73 MGB GT 2 speed wipers switch on column stalk.

Thanks

Mark
Mark

http://www.vtr.org/maintain/wiper-problem.shtml
Dan Masters

From about 1970 on the wiper parks through a normally closed contact on the manual switch. In the 'off' position the red/light-green (slow) wire is connected to the brown/light-green (park). On the wiper motor while the blades are not parked a 12v supply is connected to the brown/light-green, and hence the red/light green to run the motor. When the motor reaches the park position a switch on the motor disconnects the 12v supply from the brown/light-green and conencts an earth to it instead. This has the effect of stopping the motor pretty-well instantly, instead of it simply running down, to give a precisely (well, relatively) controlled park position.

Things that can prevent parking are lack of 12v supply to the *motor*, faulty switch on the motor, faulty contact in the manual switch, or any faulty interconnections between the three. The motor switch is contained in the plastic block the five-pin harness plugs in to. You can get an idea what is wrong by connecting a voltmeter to the brown/light-green wire e.g. at the column connector for the manual switch, with the wipers running. You should see 12v most of the time with an occasional blip to ground as the blades pass through the park position. If you don't see anything at all the circuit to the switch (brown/light-green) is broken or possibly the switch is stuck half-way between operated and released. If you see the momentary earth but not the 12v either the motor switch normally open contact is failing to close when the motor is off park or the 12v supply to the motor is missing (this is *only* used for parking). If you see both then possibly the normally closed contact in the manual switch is faulty.
Paul Hunt 2

This thread was discussed between 28/12/2006 and 29/12/2006

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