Wiper motor buzzes

[Namerow]

Agreed.  I was thinking that he could extract a suitable contact point from some non-Z relay (pref. a from an older Nissan product) and then transplant it into the relay from his Z.

[kunzma]

Opened up an extra wiper motor that I had on the shelf to compare.  Found it to also be missing the contact on the one side of the tabs.  Consulted with a specialist.  There is not supposed to be a contact there!  This is a design feature of the relay.  This tab doesn't touch when the switch is off.  I bent the tab back to it's original position.  Will have to wait on the test for a couple of weeks to see what else could be the cause of the humming.

[Captain Obvious]

Well that would explain why you didn't find the contact rattling around inside the shell.

So I'm at a loss then to explain your test results. Motor made an unhappy humming noise until you bent the tab and then it went away. But now with the tab back where it started, the humming is still gone?  Classic red herring! 

"He hates these cans!!!"

[5 Star Rising]

Old thread with no result lol...I'm having the same issue with my early 71 240z.  Im get a buzzing sound out of the wiper motor relay that is mounted to the motor. It happens when the wiper switch  is off and the ignition is on.

When I click the wipers to the on position they work fine and the buzz goes away in either slow or fast. The minute I turn off the switch the buzz starts.   

My old wiper motor was seized I couldn't turn it at all with a wrench in either direction. I had a spare wiper motor in my garage that I had for years, I could turn that shaft one direction slowly with a wrench. 

Heres the other thing. My old motor had 5 wires and the motor that I found in my garage has 6 wires..I notice an additional yellow wire for the park I assume, but my series 1 harness is only set up for 5 wires could this be my issue? Thanks 

 

 

**update.

I put my old wiper motor on the bench ,cracked it open and sprayed some electronics cleaner lube in it and on the relay. Tapped on it with a hammer, and adjusted the worm gear.

Sat it on the fender and made a temporary plug out of 5 spaded male connectors. Plugged it into the harness, hit the switch and it works great. No buzz anymore and no RPM gauge bouncing all over. Seemed like the first click on the switch was fast and the second was slow speed but oh well.  Wonder if I should put it back in the car or try to still mess with the motor that is installed and buzzing. Just worried that the old motor will seize up again down the road. 

I seen how it is supposed to operate...when you turn the switch off the motor automatically goes into reverse a few spins to seat the wipers. The motor that is in my car doesnt go into reverse it just makes noise. Wondering if that extra yellow wire needs to be connected to make the motor go in reverse or if maybe that motor relay is bad.

Edited May 2, 2018 by 5 Star Rising