WIPERS PROBLEM 280Z

ZedzDead

Club Member
Thought I had most things working now but put on the wiper arms and blades today and they swoop once or twice and stop which coincides with a loud buzzing sound (similar to a relay) in the passenger side area. Ran out of light and time to explore further today but anyone experience a similar issue or have an informed idea what it might be ? Thanks once again !
 

ZedzDead

Club Member
Quick update buzzing noise is coming from scuttle area / wiper motor, not sure why motor does one complete cycle (or wipe) on all three settings before noise starts ?
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Quick update buzzing noise is coming from scuttle area / wiper motor, not sure why motor does one complete cycle (or wipe) on all three settings before noise starts ?
Is the linkage in good condition and 'free?

The motor spins, the linkage controls the wipes (backwards and forwards).

Think I would disconnect the linkage at the motor and check that the motor continues to spin.
 
Last edited:

ZedzDead

Club Member
Appears to wipe freely Rob, but only does it the once on intermittent first and second speed then parks itself up. Somebody had exactly the same symptoms on american z forum but never resolved it by changing either motor or relay then the thread ran cold .
Will wait until I can get a lift scuttle back off and ill take a look as you suggested.
 

ZedzDead

Club Member
Right !................Battery fully charged. Separated the motor from linkage cleaned all the connections which looked pretty good and fault remains the same. Tried another windscreen wiper motor from donor car and that has exactly the same symptoms.

What is interesting is if you hold the windscreen wiper washer on ( which also don't work ) continuously on second speed the wiper motor works !

Everything previously pointed to the intermittent wiper relay on top of the motor and I guess the second one could also be faulty ? but running out of ideas fast :)
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
The windscreen washer switch runs the motor so that's fair enough. Can you imagine and English car with such an advanced feature in that period?

Let me have a think. How good are you at tracing wiring and understanding circuits?

Your Column switch is the next area to investigate I think.
 

grb184

Club Member
This might help

Understanding the 260z and 280z wiper circuit. Reverse polarity park. - Miscellaneous Tech - HybridZ

Final parking of the wiper arms. This is the clever bit which took me a while to work out. When the wipers are switched off the DC motor reverses it’s direction due to circuitry controlled by a relay strapped on to the side of the motor (this relay is used at other times too in the wiper operation). The linkage is attached to the motor via a short arm an eccentric cam bearing and coil spring. During normal operation the eccentric cam is in a position which has the effect of shortening the linkage, when the motor reverses the coil spring tightens due to the direction of travel, grips the eccentric cam, rotates it through 180’ and lengthens the linkage thus parking the wipers lower down the screen – clever eh? That’s why when switching to the off position the wiper always does a wipe – it’s to ‘park’ the wipers low down the screen
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
This might help

Understanding the 260z and 280z wiper circuit. Reverse polarity park. - Miscellaneous Tech - HybridZ

Final parking of the wiper arms. This is the clever bit which took me a while to work out. When the wipers are switched off the DC motor reverses it’s direction due to circuitry controlled by a relay strapped on to the side of the motor (this relay is used at other times too in the wiper operation). The linkage is attached to the motor via a short arm an eccentric cam bearing and coil spring. During normal operation the eccentric cam is in a position which has the effect of shortening the linkage, when the motor reverses the coil spring tightens due to the direction of travel, grips the eccentric cam, rotates it through 180’ and lengthens the linkage thus parking the wipers lower down the screen – clever eh? That’s why when switching to the off position the wiper always does a wipe – it’s to ‘park’ the wipers low down the screen


Yep found that out a few years ago - it's effective 'lower parking' process relies on a spring which is often rusted and snapped.


https://zclub.net/community/index.php?threads/wipers.18582/

If you fit a Honda motor like I did that spins in the opposite direction so you get the greater sweep (as long as the spring is ok).

 
Last edited:

ZedzDead

Club Member
The windscreen washer switch runs the motor so that's fair enough. Can you imagine and English car with such an advanced feature in that period?

Let me have a think. How good are you at tracing wiring and understanding circuits?

Your Column switch is the next area to investigate I think.

Completed my bodyshop apprenticeship in a BL dealership, no surprise that the Z pretty much finished our exports to the States, light years apart :)

Just strange that the buzzing noise is coming from the intermittent wiper relay on both motors , wouldn't be the first time that identical components have both been faulty though

Think I might have another column switch that was the next step if it appears any good. Electrics aren't my thing but will take it as far as I can Rob .
 
Last edited:

ZedzDead

Club Member
This might help

Understanding the 260z and 280z wiper circuit. Reverse polarity park. - Miscellaneous Tech - HybridZ

Final parking of the wiper arms. This is the clever bit which took me a while to work out. When the wipers are switched off the DC motor reverses it’s direction due to circuitry controlled by a relay strapped on to the side of the motor (this relay is used at other times too in the wiper operation). The linkage is attached to the motor via a short arm an eccentric cam bearing and coil spring. During normal operation the eccentric cam is in a position which has the effect of shortening the linkage, when the motor reverses the coil spring tightens due to the direction of travel, grips the eccentric cam, rotates it through 180’ and lengthens the linkage thus parking the wipers lower down the screen – clever eh? That’s why when switching to the off position the wiper always does a wipe – it’s to ‘park’ the wipers low down the screen

Thank you, I have seen both the above write ups but doesn't really give me an indication of what's occurring on my car

Was hoping for a " yep exactly the same happened on my car it was ........" sort of answer. Unlikely to happen I know but gotta ask :)
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
A guess if it's only doing one wipe then the 'parking pin' that breaks the circuit is not being over-ruled by relay contacts IMO. I need to study a diagram.
 

ZedzDead

Club Member
Final update problem solved !!!!! found home for a freshly discovered disconnected black wire under the steering column and now all working correctly

Thanks to everyone who went to the trouble to post suggestions on possible issues It is very much appreciated .........Yippeee !!!!
 
Top