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Discussion Starter #1
I actually had a toggle tied into the hot going to my wiper motor so I could get it to park properly. I'd turn the wipers off, then kill the power when it dropped into "the pocket". Otherwise it would jump up and down constantly.

I discovered during all the rain we've had lately that when running headlights and a fan to keep air moving in the car, the wipers park normally.

The difference is only about half a volt on the gauge. The wipers, headlights, and interior fan all get power from the fuse panel, which explains the voltage drop.

Apparently the higher voltage of the later model alternator causes the mechanism to go fast enough that it passes the magnet before it gets pulled into the park position (If you've ever been inside one of these things, you probably know what I'm talking about).

I need to know the wattage of the wiper motor so I can get a resistor to bring the voltage down the correct amount under normal conditions.

I plan to put the headlights on relays so they'll draw current directly from the battery rather than the fuse panel. Once I do this, I need some resistance to get the wipers to park normally.

Any ideas?

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Chad Landry
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'68 El Camino

[This message has been edited by cjlandry (edited 10-09-2002).]
 

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Well Chad,

You might find this shocking (no pun) but while working on designing an intermittent wiper system that leaves your vehicle 100% stock looking, I made some measurements.

The motor; rebuilt from autoparts store (can't remember the brand);

year: 1970 (hidden, 2-speed wipers)

Voltage 13.8 volts DC regulated bench supply

NO load on the wiper motor(this was a bench test)

During HI speed operation, the current consumption was approx. 3.5 Amps

During LO speed operation, the current consumption was approx. 5.5 Amps

No typo, lo uses more current do to "wasting" energy in the shunt windings design.
 

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Discussion Starter #3
Thanks, those figures will help.

I'm surprised that the readings are so low, but I expected the low speed to draw more current. I was guessing somewhere around 8-9 amps, but it was a wild guess, not an educated guess.

Have you completed the design for the intermittent wipers? That would be very nice. It gets old switching the wipers on and off driving behind traffic on a wet road.
 

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Coppertop,

As Chad mentioned the wippers doing funny things... I have also noticed on my 69' Chevelle that with my wipers off and in the parked position while driving down the road if I accelerate very quickly (stomp on the gas) at high RPM my wipers will come up out of the parked position.

What would cause this and would this be considered normal for year and model?

Thanks,

Brian

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<BLOCKQUOTE>quote:</font><HR>Originally posted by cjlandry:
Thanks, those figures will help.

I'm surprised that the readings are so low, but I expected the low speed to draw more current. I was guessing somewhere around 8-9 amps, but it was a wild guess, not an educated guess.

Have you completed the design for the intermittent wipers? That would be very nice. It gets old switching the wipers on and off driving behind traffic on a wet road.
<HR></BLOCKQUOTE>

Chad,

Remember, this was with 13.8 volts in, and NO mechanical load what-so-ever on the motor. If YOU get a chance to measure the current in your vehicle with the wipers in actual operation I'd love to hear the results. The intermittent wiper switch got put on hold
BUT, if my initial plans work out, this will allow you to use the factory switch in the dash and the wiring under the hood will remain 100% stock, ideal for show cars
 

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<BLOCKQUOTE>quote:</font><HR>Originally posted by fastss396man:
Coppertop,

As Chad mentioned the wippers doing funny things... I have also noticed on my 69' Chevelle that with my wipers off and in the parked position while driving down the road if I accelerate very quickly (stomp on the gas) at high RPM my wipers will come up out of the parked position.

What would cause this and would this be considered normal for year and model?

Thanks,

Brian

<HR></BLOCKQUOTE>

Brian,

The first thing is first, I'd check the ground on the motor. The rapid acceleration is probably jerking the motor on it's mounts. If you look carefully, the motor sits on rubber isolator mounts. This is done so when the motor is operating, you don't feel vibrations in the brake/gas pedals of the car. One of the rubber mounts has an eyelet and a brass strap. The purpose of this is to ensure the motor has a good ground to the firewall via one of the mounting screws. Because the motor sits on rubber, the strap allows a current path from motor body to firewall ground.

If everything looks a-ok under the hood, try this; the next time you get the urge to give it a little gas
take one hand and hold steady the switch in off position. If it doesn't do it, perhaps the switch internals are vibrating out of place ?


EDIT, just noticed you have 4-spd, might be hard to have one hand on the wheel, one on the floor shift and one
on the switch.



[This message has been edited by Coppertop (edited 10-10-2002).]
 
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