Wiper won't park nor run in low...help! Solved...Kinda

[juddster]

Recently my wiper stopped parking itself and no longer runs in low. Still goes great in high. I have the rotary switch with the relay set up. Replaced the switch and still have the issue. Measured continuity on the relay and that looks good. I haven't checked continuity when the relay is energized, but my hunch is the relay is OK. This is a new build so practically no time on the wipers except to test.

Not sure what to test at the motor. The wires seem to have good connection at the motor.

Any suggestions?

Thanks!!!

[Al_C]

If it worked initially and then stopped working, it's most likely a bad connection or the relay failed. I'd check the connections first. It's entirely possible that vibration might have loosened something at the motor.

[John Ibele]

... and if it's not that, it is time to look at the mechanical setup and see if the system has too much drag to power the wipers in low. Easiest way to debug that would be to loosen each connection slightly one at a time, and see which one is causing the mechanism to bind. It's not at all unusual (in fact maybe typical) for something to require tweaking in this system, particularly tubing length, curvature, and ensuring nothing about the flaring catches the cable.

[Nigel Allen]

The park circuit is also a part of the low speed circuit. It is likely that the low speed wire to the motor is open circuit (bad connection) or the motor low speed winding has failed.

This may help with fault finding:
When you put the wiper switch in the low speed position, it overrides the parking feature.

If you fix the low speed circuit then the parking feature will probably start working as a result.

[juddster]

The park circuit is also a part of the low speed circuit. It is likely that the low speed wire to the motor is open circuit (bad connection) or the motor low speed winding has failed.

This may help with fault finding:
When you put the wiper switch in the low speed position, it overrides the parking feature.

If you fix the low speed circuit then the parking feature will probably start working as a result.

Thanks!

I figured the two could be related.

[juddster]

... and if it's not that, it is time to look at the mechanical setup and see if the system has too much drag to power the wipers in low. Easiest way to debug that would be to loosen each connection slightly one at a time, and see which one is causing the mechanism to bind. It's not at all unusual (in fact maybe typical) for something to require tweaking in this system, particularly tubing length, curvature, and ensuring nothing about the flaring catches the cable.

Just realized that the problem didn't start until after I had finished the installation. I could easily have binding or catching going on somewhere and don't know it. Thanks!!

[juddster]

Well I loosened and checked all the potential binding points. No Luck.
The relay is all good. Can hear it energize when moving the switch to low.
Checked all the connections and checked continuity from the switch to relay to motor or switch to motor - all good.

Any other failure points that I should be checking?

[Al_C]

Do you have a diagram like this? If not, perhaps it will be of some help.

https://thefactoryfiveforum.com/attachment.php?attachmentid=191407&d=1697895881

[juddster]

Do you have a diagram like this? If not, perhaps it will be of some help.

https://thefactoryfiveforum.com/attachment.php?attachmentid=191407&d=1697895881

The diagram I used is very similar, but there are distinct differences. The one I used utilities a 5 pin relay and does not use the "P" position on the switch.

I'll give this one a try. Thanks!

[John Ibele]

Well I loosened and checked all the potential binding points. No Luck.
The relay is all good. Can hear it energize when moving the switch to low.
Checked all the connections and checked continuity from the switch to relay to motor or switch to motor - all good.

Any other failure points that I should be checking?

You also said you had this working prior to installation. That prompts this question: if you unplug the connector at the wiper motor and flip the switch to low, you get 12V at the proper pin? Because if you do, that means you have a fault inside the motor, or right at the connector.

[juddster]

The diagram I used is very similar, but there are distinct differences. The one I used utilities a 5 pin relay and does not use the "P" position on the switch.

I'll give this one a try. Thanks!

Tried it. No luck. Had a hunch it wouldn't but it was an easy change to try.

[juddster]

You also said you had this working prior to installation. That prompts this question: if you unplug the connector at the wiper motor and flip the switch to low, you get 12V at the proper pin? Because if you do, that means you have a fault inside the motor, or right at the connector.

Thanks John. 12V at the low connector. So fault in the motor or at the connector. Does this happen often? Need to replace the motor?

[Nigel Allen]

Certainly does appear that the low speed winding has burned out. To be sure of this, it is worth opening the motor up and doing a sniff test to smell for burnt windings. This is important. If the winding has burnt out, it will be an indication of too much mechanical load. If there is a mechanical overload and it is not resolved, then replacing the motor will just repeat the failure.
The characteristic of a DC motor is that it will continue to draw more current as the load is increased. Once the current exceeds the rating of the motor, it is only a matter of time before it cooks itself.

[juddster]

Certainly does appear that the low speed winding has burned out. To be sure of this, it is worth opening the motor up and doing a sniff test to smell for burnt windings. This is important. If the winding has burnt out, it will be an indication of too much mechanical load. If there is a mechanical overload and it is not resolved, then replacing the motor will just repeat the failure.
The characteristic of a DC motor is that it will continue to draw more current as the load is increased. Once the current exceeds the rating of the motor, it is only a matter of time before it cooks itself.

Opened up the motor and there is no notable smell of burnt windings. Nothing else seemed out of place or burnt in any way. Course, not sure exactly what I should be looking for. Can the pins be bad? Or the connector right on the motor? About ready to just buy a new one.

[Nigel Allen]

It is possible you just have a bad connection. Although where it might be unfortunately is anyone's guess.

[juddster]

Well after trying a new wiper motor and it not working things got frustrating. I decided to put the old one back in and start testing my wiring again. After I installed the old motor it started working! No idea why. There must have been a poor connection somewhere or I flat out missed something.