I have a question regarding electric wiper motors. I was planing to use the wiper motor from a chevy pickup that I have as a donor. When it was still hooked up the wipers would park in the down position. Now that I have the linkage disconnected the motor continues to rotate with the wiper switch turned off and will only stop when you turn off the ignition key. I was hoping that the motor would self park so I could use it in my 56. Are all motors not treated equal?
John

 

try a seperate/adding a ground to the motor casing.
the park curcuit is likely missing it and just bypass's the signal and goes into another sweep.

 

Did you use the switch from the Chebby truck as well? All motors are not equal, especially between GM and Ford. Often the parking is a function of the switch. But if you have the Chebby switch and install it with the motor it should park "somewhere."

 

I knew I could count on you Julies to respond. I had it plugged back in the truck I took it out of but not hooked up to the wiper linkage. A friend of mine said that it probably needs to find a place to park and not being hooked up can't get that signal, does that make sense?

John

 

i might be newb but hey.
even in 74 the park curcuit was in the motor. try grounding the case.
http://www.rowand.net/Shop/Tech/imag...erDiagram1.jpg

 

Thanks for that explanation, I'm going to go out and try your suggestion. Could you post the rest of that article please and thank you. I'll let you know how I made out. Later...John

 

Delay Wipers

no problem.
sorry if i came across rude.
just some guys don't give newb's the benefit of the doubt.

 

Hi

Yep makes perfect sense. Wiper parking is as much a function of Voodoo as science. There is a relationship between the motor and switch that causes the wipers to park. I can conceptualize it in my mind but it wouldbe more confusing to try to write it down. Basically, it has to do with the position of the switch that causes (or tolerates) either mechanical or electronic cut outs that elliminate power or ground to the motor to stop the wipers in a certain place.

So the consistency in type between the motor and switch is important.

If you hook up the switch for the wiper motor you have, it will park the wipers. But that position is a function of the angle it was designed to stop at the motor to put it's stock chevy wipers down with the chevy linkages. It will stop at that angle at the motor now as well, but whether or not your wiper linkage is in the correct position to park the wipers down where they are supposed to be remains to be seen.

Did that make any sense?

 

You might be a newbie and I didn't think you were rude. I've been working on this build since spring of 2005 and I feel as though I'm still wet behind the ears. I value the input of eeveryone on here, and by the way welcome to this site, your imput is very much appreciated.
Now to what I did this morning. I plugged the motor back into the pickup, grounded the main frame of the motor,both to the body of the truck and directly to the battery terminal, with the switch in the off position, it still continues to rotate. I don't know if when I tried to start the motor on my bench if I could have shorted something out. I may have to see if I can get another motor to see if that is my problem.
What I'm trying to do in imitate what New Port Wipers did without the expence of purchasing thier wiper motor, every time I purchase something it ends up costing me twice as much as what they're asking, cross border shopping is expensive. I'll post some pictures of what I've done so far.

 

Yes ...I ,think so. I'd like to be able to hook everything back up on the chevy just to check if some how I didn't screw up the motor but can't because I had to modify the arm that bolts to the motor to fit my application. If I can't get this figured out I may just have to dig down deep into my pockets and buy the wiper motor from Newport.
John

 

This is what I've done and think it should work if I can get the motor to park

 

I have wiper motor diagrams in my gallery that may help. If you have trouble reading them I can send out Larger PDF's

T900

 

HI again.

Also, if you can get a wiring diagram from the chevy to make sure you have all the wires hooked up correctly, that might help.

I migth also be tempted not to add any grounds outside of that is on the switch and motor originally, some of these motors park by ellimination of the ground created by an eccentric cam and set of points. If it has a constant ground, the points may be bypassed.

 

Good morning Julies, thanks again for your reply. The tests I've done so far has been hooked up to the chevy, just sitting on top of the intake breather, I've done the grounding the case thing but it's like a Timex just keeps ticking with the switch in the off position. I'm beginning to think that I messed things up when I tried starting it on the bench and arced out the leads. When hooked up to the chevy switching through the different speeds there doesn't seem to be any change. There is a fellow in town that has a yard full of chevy's and I'll have to see if I can score another motor from him but that might take a few days as he is hard to get hold of.

 

Actually parking/and intermittent is pretty easy once explained..

motor needs power & ground to run.. when the switch is ON, its pretty easy.. but.. ad the thought that you want the motor to STOP in a specific spot ALL the time.. hmm...

the trick.. when the motor starts to turn, it moves a (spring loaded) tab that supplies power to the motor into connected state.. so you have TWO power feeds.. one from the switch, and one internal..

the ring that pushed the connector up has a gap in it.. and so, when the armature gets around to that point, the connector disconnects, and if the primary feed wire is off, then the motor stops.. this is the end of the cycle.

intermittent starts it back up again by pulsing the primary feed, which starts the motor, pushes the connector back up, drops the primary lead, and one cycle the connector drops and poof, off again..

the intermittent logic can have a variable delay time.. or positional fixed delay times..

so, intermittent is really just repeating parking!!..
the 'park' position is a factor of the motor rotation, the motor arm length, etc,etc... the motor doesn't know anything about the wipers themselves.. it just goes around til it runs out of power..


Sam