In a message dated 4/20/99 7:05:08 PM Eastern Daylight Time,
RVincenti@lbfc.com writes:
> Brad - Hmmm, help me here. Why would there need to be an additional
> wire? After all, 12 volts is 12 volts, whether fed to an electric
> motor by one wire or two. Wouldn't the speed govenor be built into
> the wiper motor itself?
Ross,
You're sorta right, and sorta not right. Speed control is built into the
motor, but the two speeds are externally switched. Feed power to one motor
lead and it runs slow - feed power to another motor lead, and it runs fast.
Refer to: http://www.vtr.org/maintain/wiper-motor/
For details on how this works on one of the later wiper motors.
The two speed motors on the earlier TRs switched ground, rather than power,
but they still used two wires from the switch to do it. Tony Rhodes
<ARhodes@compuserve.com> and I were working out the details of the wiring for
this motor just before I signed off awhile back. I think we got the details
resolved, but I'm not sure. Contact him, Brad, and see if he doesn't have the
info you need. If not, maybe he and I can get together again and finish it
up, and get the details to you. The switching arrangement on these motors is
a bit of an oddity.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://members.aol.com/danmas/
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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