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4 wire wiper motor into 3 wire plug

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jimdubose

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Discussion starter · #1 ·
my three wire wiper motor is toast, i was given a 78 windshield frame and broken windshield and working four wire wiper motor (obviously not a 78). have reworked the frame (I will post pix, looks great, chose to go this way after reading so many posts about what junk aftermarket replacement windshield frames are), had it welded, sanded, primed, painted it, replaced the windshield and am waiting for a replacement windshield left hinge to replace the one which broke when i removed my windshield frame. the four wire wiper motor works (i have tested it with the battery and ground) and i am going to install it and utilize the three wire switch (i tested it previously with a meter directly to the battery, it appears to work). to me simplest is best and since the four wire motor has red, green, black and blue wires, and the three wire motor has red, green and black, i am thinking simplest is to cut the conectors off of each and but splice the reds, greens and blacks and leave out the blue (i have scoured this and other forums and though confused, feel that the blue wire goes to the intermittant apparatus) because all i want is high, low, park and off, and with the three wires from the four wire motor connected to the three wire connector, then plug that connector into the back of the switch and off to the races and search the sky for rainclouds. am i making this all too simple? am i just crazy? will this work?

thanks for your answers
 
Discussion starter · #3 ·
i wired up the three wire plug to the four wire motor, red to red. green to green, black to black, leaving out the blue wire, grounded the motor to the frame and set it on the front seat have fast and slow motion using the switch on the dash, but when i go to off, it stops where ever i cut the power with the switch, telling me it isn't parking the wipers. i don't mind ****ting it on and off this way, but would rather it parked them like it is supposed to. any suggestions as to what i may have done incorrectly? or does the linkage have to be hooked up to accomplish the parking maneuver? i wouldn't think so. seems it should continue to move to position when you switch the switch to off regardless of whether the motor is installed. from what i have read, the switch itself is supposed to be grounded for the park function to operate correctly? i have had to clean up everything else on the dash panel to make things ground correctly, so this switch should be no exception, if this is the case. i am putting a dedicated ground on the wiper motor when i reinstall it and not going to rely on the ground through the windshield hinges, i grounded it with a dedicated ground to test the switch. any thoughts based on this additional information? suggestions? thanks for your input.
 
#4 ·
jim we use the three wire four wire motors on the heavy equipment i work on daily and as you have mentioned i have not found a difference. if your motor continues to turn for a second or two after the switch is turned off the park function may be dependant on the regulator. many wiper systems rely on the regulator for at least part of the park function. is the shaft out of the wiper motor indexed? or is it just splined? if it is indexed and the motor continues to spin after the switch is turned off then the park function is all in the motor.
 
Discussion starter · #5 ·
clearly, I do not understand everything i know about these little wiper motors, and in all my ignorance, i honestly do not know the difference in looking at what i can see of it whether the shaft is splined or indexed. before i attached the three wire plug to the red, green and black wires and left off the blue, i powered up all four wires seperately and only got movement of the arm with the red and green wires. power to the black and blue did nothing. when i wired the red, back and green through the switch, i got the high and low speeds, but no matter where the arm was when i switched the switch to the off position, the arm stopped exactly where it was when i cut power and did not continue on to any park position. i tried it numerous times and each time it stopped wherever it was when i cut power (five times, five different locations, never continuing to a common spot, which i could have assumed was the park position). the motor does not continue to move for a second or two, or at all. everything i have read from John strenk and others, scouring old posts, says the park function is inherent to the motor. i can't figger out how to make it do what it is supposed to. wondering if the blue wire is the park function wire, not the black? things i have read yet maybe don't grasp is that the park wire is always hot, and the motor has the capability to short itself then the motor turns to the correct position and that the grounding to keep that wire hot is independent of the motor to frame grounding for the high and low speeds. somebody with a bigger brain than mine needs to educate me, or at least tell me if i have my facts wrong. thanks for your response, jcarr, does this make it any easier for you to tell me what i am missing here? and anyone else? thanks
 
#6 ·
try touching the blue wire to a 12vdc + source after turning the switch off if the motor moves to a common position then its the park wire. if you have an arm on the wiper motor then you won't be able to tell if its is indexed or splined until you remove the arm. start with powering up the blue wire after the switch is off and see where that gets you. oh be sure to use a fused circuit just for safety sake.
 
Discussion starter · #7 ·
since i just have the black to black and the red to red and green to green wire nutted together and not butt spliced yet, would it be ok to just unwire-nut the black and reconnect it with the blue for this test, or does the black need to stay wired and jumper power to the blue? if i gotta have the blue and the black, then the whole four to three concept i am looking at isn't going to work. thanks
 
Discussion starter · #9 ·
disconnected the black, hooked up the blue, absolutely the same result. went back to black to black. i'm grateful to have the wipers, irregardless of where the stop, whether or not they park. since i got no doors and only a bikini top, another problem is keeping blowing rain off of the inside of the windshield, but i'll address that later. also have a broken windshield hinge bolt with a broken easy out imbedded in it on the right side of the windshield frame. any takers on how to get that out? (I broke off the easy out in there, dumb, huh?) thanks
 
#13 ·
According to the '84-'86 FSM, the wires coming from the motor should be red, wht, blk, blu.

Pg 71 of the pdf above shows that blue is high, white is low, blk is ground, and red is Park. Not sure if this helps you or not, but there it is.

Many thanks, again, to CJ Chet for scanning the FSM, and JeepHammer for hosting the files for all to see.
http://www.jeepforum.com/forum/f8/84-86-factory-service-manual-750127/index2.html

edit: dslywalker beat me to it...
 
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Discussion starter · #14 ·
i wonder what year my motor is then, because the wires are red, green, blue and black. wired into the three way switch, the gree wire gets the first click and that runs low, then the second click gives the switch to the red. if that is the park switch, woouldn't the motor move the armature to the park position, short itself and stop the motion? instead, it runs in high speed when you put power to the red wire. and is the white really the green? my wiring diagram shows that the motor grounds through the mounts without a ground wire. this is getting more confusing as we proceed.
 
#15 ·
My motor is out of a 83 and just like yours, so i think its just a printing or factory error.A 2 speed switch/3 wire motor doesn't have a blue wire.Just Black/Red and Green
The park switch would park the motor.Your park switch would be inside the motor.The motor grounds thru the window frame.
Do you just have 2 speeds right now?
Print shows blue-hi
white which could be green=low
black=park
red=power in
A lot would be what terminal they go on the switch which is 3 speed
I might have a print of a 3 speed switch i'll look
 
Discussion starter · #17 ·
what i have is red-high, green-low, black and blue do nothing when you put current through them and ground the motor. i have a 78 wiring diagram, and composites of switches a/la John Strenk taken from this forum. both the black and the blue wires do nothing when jumper them to the positive battery terminal when i ground the motor body to the negative. same thing through the three way switch when i wire the red, black and green through it. no white wire.

the only other thing i can think to try is to keep pestering you guys and google places and check and see if the switch has a ground itself for the park function to ground through and possibly that is all that is missing. if push comes to shove, i'll have to use em without the park function until i can figger it out. i don't have that switch like the pix you posted, i have the three wire switch that came with the 78 (five prongs, not seven like the pic), and the motor i have with the four wires (which I was given), the wires come to a halt at a connector terminal, flat, four small connectors, one for each wire, to plug into a female connector and then toward the switch and i would imagine somewhere in there the intermittant electrical apparatus i have seen in other posts. i believe the blue gets its feed from that intermittant unit, but don't know.

btw, i drilled out the frozen windshield hinge bolt and the broken easy out with a cobalt drill bit from NAPA, rethreaded the hole with a 5/16 tap. thanks for any advice on this wiper thing, guys
 
Discussion starter · #20 ·
Yeah, that's it, as you have probably noticed, there is no where for the blue wire in this scheme. my wiper motor has never worked, it was locked up when i bought the jeep. when i began this windshield frame replacement, the frame came with the four wire motor, which does work (except it does not park the wiper motion when connected to a battery, or through the switch). i don't know if the old motor parked or not, because it has been permanently parked. with or without the blue wire, somehow it should be able to park, i just can't get any response out of either the black or blue wires, only red and green, i have both of these figures downloaded, as well. just hoped someone had faced this before
 
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jimdubose
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