In a message dated 97-12-20 01:48:35 EST, you write:
> Do not know, but I do know that I have had to do this step on more then one
> occasion. It worked for me.
>
> I would like to know why, because it surprised the hell out of me the first
> time that I had to do it.
Mark:
You got me! I don't understand why. Maybe I am misunderstanding what you mean
by moving the switch 180 degrees.
I have taken apart several wiper motor assemblies (Triumphs and MGs), and on
all of them, the direction of rotation made no difference in the operation of
the wipers themselves.
Just for discussion, let's assume the motor is at an arbitrary reference angle
of "0" degrees, and the reciprocating arm is at its maximum extension. Now, if
we rotate the motor CW 180 degrees from this reference angle, the arm will be
at its minimum extension. The same is true If we rotate the motor 180 degrees
from "0" in the CCW direction. Since the wipers must park in either the full
maximum or the full extended arm position, ie, 0 or 180 degrees of rotation,
swapping the switch 180 degrees will cause the wipers to park on the opposite
side of the windshield from before (if they parked with the arm in an
intermediate position, they would park in mid travel).
Obviously, I'm missing something if you've had to swap the switch to make them
work, but I can't think of what it is. On all of the wipers that I have looked
at, the motors are of the permanent magnet type, so they will rotate in
reverse if polarity is reversed, but they also all came from negative ground
cars, so I don't know what type was used on the earlier positive ground cars.
If anyone has the key to this puzzle, please fill us in!
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
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