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Re: 78 westy

Posted: Sun Jan 21, 2018 12:06 pm
by Karl Kombi
Cool -- thanks for the pics! I feel your pain with having no heat... :(

Re: 78 westy

Posted: Sun Jan 21, 2018 7:02 pm
by Six Volt
Do us all a favor and document everything like Bruce and Chuck so we can all follow along. Good luck!

Re: 78 westy

Posted: Mon Jan 22, 2018 8:33 am
by Ken
It looks like you picked the right team of players for your project. Should be interesting and looking forward to the build.

Re: 78 westy

Posted: Mon Jan 22, 2018 11:21 am
by heyed67
awesome..looks like you have had your hands full..cant wait to see er done. :D

Re: 78 westy

Posted: Sun Jan 28, 2018 7:18 pm
by ohiowesty
Six Volt wrote: Sun Jan 21, 2018 7:02 pm Do us all a favor and document everything like Bruce and Chuck so we can all follow along. Good luck!
Here you go, Sean :D . Some of this stuff may seem very simple but for someone else like me, learning on the fly, may be helpful!
I had a few hours to myself on Sunday so I decided to tackle the wiper issue: there is no difference between hi and low speed - they are both just excruciatingly slow - and sometimes the wipers don't park themselves.
This is the wiper assembly
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I could tell that the wiper has been messed with so I started by checking if it is year appropriate (1978). It appears that all 12 volt wipers have the same part number digits - 211 955 113 followed by a letter indicating the years. G is 67 only, H for 68-72, L for 73-??, E for ???, Q for late bay. Brazilian wipers end in a number instead of a letter. Mine checked out ok!
IMG_20180127_220318 resized.jpg
As a side note, I found out that the Champagne Editions came with an intermittent wiper option.
The Bentley manual troubleshooting for slow wipers basically boils it down to two factors: motor problem or dry/dirty moving parts.
I decided to test the motor first. To me, the wiper wiring diagram is confusing to say the least; and having 5 wires to work with, I struggled to understand what does what.
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Re: 78 westy

Posted: Sun Jan 28, 2018 7:31 pm
by ohiowesty
This video shed some light: https://www.youtube.com/watch?v=1Ww5-pmiokc
but this excellent second video really made things click, and also showed how exactly, 40 years ago, our wipers used regenerative braking technology - eat your heart out Prius!
https://www.youtube.com/watch?v=a7qJy8mYi6s
Out of the 5 wires, the brown one is obviously the ground so I clamped it to the negative side of the battery. On the socket side, I insulated the connector with electrical tape to prevent touching it when I test the other terminals.
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Then I hooked up the red wire to the positive battery terminal like so, and it turned out to be the high speed.
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Repeat the process for green - turns out to be low speed. On blue and white - nothing. Notice how the green and red wire go directly inside the motor, while the blue and white ones attach to the transmission housing.
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Inside the housing, there is a separately powered parking switch, that still powers the wipers after you turn them off. Otherwise, they would stop randomly on the windshield. I treated blue and white as a simple switch: power from battery enters the blue wire, comes out the white, then jumps to the red one to the motor, and it exits through the brown ground wire back to the battery.
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Re: 78 westy

Posted: Sun Jan 28, 2018 7:39 pm
by ohiowesty
Tested it like in the drawing above,and the wipers parked themselves. Here is the jumper on the socket.
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So during bench testing, everything turned out to be working properly. Back to the original issue: slow wipers, no difference between high-low speed. Maybe the motor is weak. To evaluate the motor condition, the Bentley manual calls for current draw testing: about 2.5 amps at low speed, 3.5amps at high speed, wiper blades pulled away from windshield. To measure current draw, set the multimeter to amps/DC and connect it between the positive battery terminal and the red wire terminal on the socket. like so:
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Then repeat for the green wire. Both checked out good.
To simulate load (weight of blades+weight of snow+windshield friction) I held onto the wiper linkage while operating the assembly. No problems there; therefore, I probably had a weak ground or a bad connection when the assembly was in the bus.
Next step is to take all linkages apart, clean the grime and lube everything properly. Next time!

Re: 78 westy

Posted: Sun Jan 28, 2018 10:36 pm
by Dual Port
It's common on older VW's for the wiper shafts to seize up from salt water going down the shaft. (I don't know if this applies to Bays or not) Can you disconnect them and test for being free? Can you remove and lube the shafts?

Re: 78 westy

Posted: Sun Jan 28, 2018 11:19 pm
by ohiowesty
Yes they are removable. Surprisingly there are a couple of NOS shaft rebuild kits on samba https://www.thesamba.com/vw/classifieds ... id=1668590

Re: 78 westy

Posted: Mon Jan 29, 2018 9:35 am
by Six Volt
Excellent write up. Thank you for the documentation.