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Discussion Starter · #1 ·
I have read of some people having problems with their Lucas wipers parking due to insufficient resistance (even with everything assembled), especially from high speed.

I have seen Wade's diagram and the comment that using this setup the wipers always park, even from high speed.

Can anyone confirm this? I need the wipers to park to pass.

Thanks.

Garnet
 

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FFCobra Master Craftsman
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Hi.

Where can I find that diagram?
Can you post it, or send me a mail?

Cheers,

Olivier
 

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I would recommend parking in low speed. I originally had my circuit set up to park in high speed and found that if the windshield was wet (relatively low friction), that the wiper motor has just enough inertia to sweep right on past the internal "park" microswitch! The result is the wipers continue to run in high speed, even w/ the switch off! Never had the problem while testing (dry windshield), and only occasionally had the problem in the rain.

I rewired for low speed park, and it's been perfect since then. :D
The link that John posted above is the newer "low speed" park option.
 

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Discussion Starter · #7 ·
That link does not have a diagram. Does the diagram below have the circuit parking from High or Low?

http://www.quickkeys.com/Cobra/wiper%20wiring.jpg

Part of my confusion is that I do not understand what the V post does in the motor. Doesn't the current run from H, L or P to G?

Also wondering what you think of this circuit.

http://www.geocities.com/sprite-midget/wipers.htm

Since I require park to pass I may go with the Lucas switch, as long as it will park 100% of the time.

Regards.

Garnet
 

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that first link is the same picture that's embedded in the word doc. "V" is +12V switched power. It's connected internally to the "P" (park) terminal through a normally closed microswitch. There's a little cam on the driven gear in the wiper motor gearbox that trips the microswitch in the "parked" position.

If the wipers are anywhere in the sweep, other than the park position, there is 12V being fed to the P terminal. When the main control switch is "off", the 12V from the P terminal powers the motor (on low speed) until it sweeps far enough to trip the internal microswitch, which then removes power from the P terminal and the wipers stop! :D

Some folks have reported the setup in that geocities link blows fuses. I've never tried it myself.
 

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FFCobra Craftsman
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I tried the geocities' link schematic. If I went directly to high from the off position the fuse would blow. It would also blow if the switch was in high when power was applied to the circuit. I modified the circuit as required to get it to work. That's the diagram I posted. Even if you have my circuit in high speed, as soon as you move the switch to off the relay relaxes and the motor runs in low speed until the wipers are in the park position.
 

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Paul,

Could you number the relay terminals? Looks like terminal 30 goes to pin 5, pin 3 goes to the high speed position on the switch, pin 4 is the power, terminal 85 goes to ground, but I'm a little confused on terminals 86, 87 and 87A. Does pin 2 go to 87A? Terminal 87 to low speed position? It looks like you splice the wire from 86 to both high and low speed positions on the switch as well as pin 3. Is that correct?

David Townsend
 

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I hope I didn't give anybody the wrong idea about the whole low speed park thing. I didn't mean to imply that you had to move the switch to off only from the low speed position. Like Paul's design, if the switch is moved from "high" to off, the relays will first put it into low speed, then it parks. All automatic. Either circuit will work great. I chose to use two relays. Paul used one relay and diodes. :D
 

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Wade, so that's what is happening! I've had the same problem for a couple of years and couldn't figure it out. Thought the park switch was defective or was just part of the Lucas charm we have come to love.They work perfectly in dry weather but at least stick in the on position in the rain so I've just lived with it.Now I know. Thanks for posting. Pete.
 

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David, yes, terminal 87A connects to pin #2 and terminal 87 goes to the low speed side of the switch. And terminal 86 receives power from the high or low speed side of the switch.
 

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Paul,

Okay, I promise, last question on this. Wade mentions diodes when referring to your circuit diagram. Would those be the "arrows" on the LB/R and LB wires? As always, thanks for your help.

David
 

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Yes, an arrow with a line at the pointy end is the symbol for a diode. The one going to the high speed terminal of the motor needs to be rated for at least 3 or 4 amps. The other two can be .25 or .50 amp rated diodes. The end of the diode with the stripe around it is the negative side of the diode.
 
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