Wiper delay unit
- Thread starter Lewis Stephens
- Start date
On my car, and I'm assuming on yours, the self park system works like this.
When you turn the wipers off, the ignition still gives the wipers a live feed through the wiring block on the side of the motor. This keeps the wipers moving until the internal switch in the block gets turned off, by the bridge on the wheel in the pic below hitting the switch shown by the black arrow. Mine didn't work because the screws (arrowed red) and the wiring block had come loose, so the bridge just pushed the wiring block away from the motor without activating the switch.
I hope that makes sense
Try moving the wiring block about, to see if it has come loose.
When you turn the wipers off, the ignition still gives the wipers a live feed through the wiring block on the side of the motor. This keeps the wipers moving until the internal switch in the block gets turned off, by the bridge on the wheel in the pic below hitting the switch shown by the black arrow. Mine didn't work because the screws (arrowed red) and the wiring block had come loose, so the bridge just pushed the wiring block away from the motor without activating the switch.
I hope that makes sense
Try moving the wiring block about, to see if it has come loose.
jp928
Well-Known Member
here is the insides of the delay thing
The nylon cap on the rod just pulls off.
There are 2 sets of contacts (2 spade connectors, top) one of which is fed at a time from the single spade . test with a meter that they conduct from the single spade to only one of the 2 spades at a time. these contacts might need cleaning (narrow strip of wet-n-dry abrasive) if they dont conduct. The condition of the metal cup on the diaphragm is not relevant, it just pushes the contact brass fron one contact to the other. The clips holding the body together can be trick to refit, take care not to lose any.
The nylon cap on the rod just pulls off.
There are 2 sets of contacts (2 spade connectors, top) one of which is fed at a time from the single spade . test with a meter that they conduct from the single spade to only one of the 2 spades at a time. these contacts might need cleaning (narrow strip of wet-n-dry abrasive) if they dont conduct. The condition of the metal cup on the diaphragm is not relevant, it just pushes the contact brass fron one contact to the other. The clips holding the body together can be trick to refit, take care not to lose any.
Excellent advice! I didn't know how the park function was activated so I was gong to have to do some research and exploration into the motor. Your discussion and picture takes much of the guess work out of it. So very much appreciated. DrewOn my car, and I'm assuming on yours, the self park system works like this.
When you turn the wipers off, the ignition still gives the wipers a live feed through the wiring block on the side of the motor. This keeps the wipers moving until the internal switch in the block gets turned off, by the bridge on the wheel in the pic below hitting the switch shown by the black arrow. Mine didn't work because the screws (arrowed red) and the wiring block had come loose, so the bridge just pushed the wiring block away from the motor without activating the switch.
I hope that makes sense
Try moving the wiring block about, to see if it has come loose.
View attachment 25322
Thank you for the advice. Did you see Quatro's explanation of the park function switch below? I'm wondering if my situation is different, because the wipers cease movement immediately when the switch is turned off. It would seem to me that if the internal switch was not being activated, as in Quatro's case, the wipers would continue in motion and not stop at all.
Drew
colnerov
Well-Known Member
Yes, that may be true but it doesn't stop the switch being faulty. Clean all the grease out, re-assemble it dry and bench test before putting grease back in it. Be aware that you will need some sort of load on the gear wheel, just run your thumb against it otherwise the ramp on the gear wheel may overshoot the switch with the momentum of the motor and gearwheel.
Will do. Again, many thanks!
I think that this is, indeed, happening in some fashion. I'm going to remove the assembly and take a look at it. Thanks for your help.
Gentlemen:
Further information investigating the park function will be appreciated! I spent the weekend addressing my windshield wipers' failure to "park". This is what I learned: 1) The wiper motor and mechanism appear intact and of normal function. Nothing was loose, missing, or broken. The ramp on the gearwheel that activates the park switch is intact and makes contact with the park switch as it should. 2) The "park" switch itself is functional. I manually depressed the "park" switch while attaching a multimeter to the spade wire connector. A circuit was completed each time the switch was manually depressed, and, the circuit was opened when I released pressure on the switch. So, I know the park mechanism works, and, that there is an electrical connection made when the park mechanism is activated. Still, the wipers will not park. They remain wherever they are when the wiper switch is turned off. To my way of thinking, this means that once the wiper switch is turned off, the normal electrical current that should remain in the system and power the wiper blades until the "park" switch is activated is not there. Any insight is greatly appreciated. Drew
Further information investigating the park function will be appreciated! I spent the weekend addressing my windshield wipers' failure to "park". This is what I learned: 1) The wiper motor and mechanism appear intact and of normal function. Nothing was loose, missing, or broken. The ramp on the gearwheel that activates the park switch is intact and makes contact with the park switch as it should. 2) The "park" switch itself is functional. I manually depressed the "park" switch while attaching a multimeter to the spade wire connector. A circuit was completed each time the switch was manually depressed, and, the circuit was opened when I released pressure on the switch. So, I know the park mechanism works, and, that there is an electrical connection made when the park mechanism is activated. Still, the wipers will not park. They remain wherever they are when the wiper switch is turned off. To my way of thinking, this means that once the wiper switch is turned off, the normal electrical current that should remain in the system and power the wiper blades until the "park" switch is activated is not there. Any insight is greatly appreciated. Drew
Last edited:
sdibbers
Well-Known Member
*nothing*?
"Nothing" is pretty much correct. I still don't understand why the wipers don't park. My primary problem is that I don't fully understand the "park" function. I suspect, at this point, that I have a wiring problem, but, I'm hoping to learn more from forum members.
roverp480
Active Member
This is a diagram of the principal of the self park system. There's a permeant live to the park contacts which keep the motor running when the motor is switched off until the park contacts open with the cam. At the same time the park contact change over to connecting both poles of the motor to earth so stalling it. Its important that the main switch on the dash is working correctly as it forms part of the circuit even when switched off.
Attachments
Last edited:
The electrical aspect is what I will pursue next. Many thanks! Drew
This schematic is incredibly helpful. Having convinced myself (to this point at least) that the system is sound mechanically, this is what I needed to troubleshoot the electrics. I will start with the switch on the dash. Very much appreciated! Drew
Genrlemen: I’ve noticed that some discussions of removing/repairing/refitting the wiper motor include a step in which one removes the earth wire from the wiper motor prior to removing the motor. Do all 3500 (1972 Series 2) P6s have this earth wire? There was not one attached when I removed the wiper motor from my car.
Thanks in advance.
Drew
Thanks in advance.
Drew
I think an earlier version had them.