After reading up on all the things that can prevent
81 wipers from working, I dug into it.

Took out the control board and checked all the solder
connections (good) and cleaned the board. Have power
in on the brown/white, and the black ground is good.
So far, so good, but no wipers.

Painstakingly disassembled all wires out of the plugs and
cleaned the connections. Continuity all up and down the line,
still no wipers.

Replaced the switch, still no wipers.

Finally found out how to test the motor - no good.

Ordered a rebuilt motor at a reasonable price, got
it quickly, carefully installed it, STILL NO WIPERS!

Checked out the new motor, NO GOOD!

Why me, Lord!?

Waiting to get my replacement motor.
Still don't know if the darn board is any good, either.

What a trip!!

Just in case - anybody know anybody that tests these
boards (check the individual components electrically)
and repairs them / replaces bad components?

With all the trouble with these boards, seems there
should be a market out there for somebody who can
do that!

 

My 81's wipers are evil too... They work when they damn well feel like it. I think it's the switch though, because I got mad a couple times and hit the switch, and they started working... It's not too cool to go on a date with a girl, and have to hit the switch to make it work... Where did you buy your switch? I found one at Ecklers for $34.99, but I'm curious if there's a better deal out there somewhere... What's the point of the circuit board? Can't we just bypass the thing by rewiring?

 

:D

How do you test the motor? I posted one today about some voltage findings on mine today but; have had no responses as of yet. . .

How much are the motors?
:confused:

 

When you say the "controll board" are you talking about the one behind the passanger seat ? Under the plastic storage compartment. I had this same nightmare on my 80 not to long ago and thats what it turned out to be.

 

That price is about the best going - I checked all around
the other places I know (the switch)

Eckler's had the best deal on a rebuilt motor - about $95.
Other places sell new ones that range up to as much as
nearly $150 .

A gentleman in the UK told me that the motor could be
tested like this: The center/white wire on the plug is
the power in, so hook up power to that lug. Then ground
the lug for the purple wire (top lug, "high" speed) and
the motor should turn. Apparently the switch just grounds
the motor to make it work - there's power in via the white
wire at all times the key is on. If you add ground to the
gray/black wire, bottom lug, that should make it run in "lo"
Then removing the ground for the top lug should make it
park.

One thing I noticed on the motor I got was a sticker that
said the motor had been test run on an oscilloscope and
tested good. This may be significant - It also said not to
test run the motor without hooking everything up as it would
cause reverse polarity and cause the motor to jam.

That's just how it acts. When I hooked everything up and
first tried it (checked out board connections, power to the
board good, and all grounds good, new switch, etc) all the
motor did was click when I turned the switch on. After that,
I tried testing it as above, leaving he pink wire hooked to the
other end of the cover (I guess that's what works the "park"
function?). It would spark a little and click inside the motor
when I made the ground connection to the top lug in an attempt
to simulate "hi" gear via the switch but still no motor operation.

I'm now wondering if the motor is in a locked up condition
as described on the sticker - maybe due to a problem in
the control board (?) I've emailed Eckler's tech svc dept
to see if they may have some info.

One would think that there would be a way to "unjam" the
motor if that is the case, we'll see what Eckler has to say.

I was also thinking that, as all the switch does is to ground
the purple and the gray/black wires for hi and lo that it
might be possible to jumper some ground to the right terminals
from the switch to at least get hi and lo working - I bought
this thing last fall and still can't license it because it won't
pass safety inspection without these wipers working!

There HAS to be a way to either upgrade that whole system to
like a C4 or other later model Chevrolet configuration, or
something to get this problem solved once and for all!!

Maybe I'll try posting a question on the C4 board about how
their systems are set up.

 

Looking at the diagram in the Shop Manual, it appears
the control board works the delay function for sure,
and also the washer function. Trouble is, all the
wipers go to or thru that thing, and even the Shop Manual
doesn't give much in the way of troubleshooting beyond
checking fuses!

 

Yes, that's the evil little piece of crap! You say you had
the same problem and that's what it turned out to be -
how did you fix the problem? Did you find and spend
the big $ for a new board? I understand they're not
made any more, an when they were, they were
exhorbitantly high $.

 

You say that the wiper motor gets constant power, it's just the ground that operates it, correct? So why not run a wire from the wiper motor to a switch in the cab that just supplies a ground. I know it's "bubba" but if you've been waiting a year for this car to pass safety inspections, it might be worth it.

 

Let me know what Ecklers says.

I'm very curious as I have an issue with mine as well.
See my post about testing with a volt meter.

Mine also clicks.

Good Luck!!
:thumbs:

 

I took a look at an 84 wiper motor on an online catalogue -
different than ours, but looks like the basic configuration
and might fit in the stock location pretty easily.

Also looked at an 84 wiper switch - nearly identical!

Think I'll go to the library and check out the wiring
diagram and maybe troubleshooting in the big Chilton
to see how they're wired up and maybe figure out if
they have a separate control box for the intermittent
or if it's all in the motor like many other later model
vehicles.

Might just be a (relatively) easy solution to replace
our whole mess with a C4 setup! Might be too
much to expect, but I'm going to take a look.

 

Excellent!
Let me know how your investigation goes. . .
:thumbs:

 

Well, of course the local library is closed Sundays
for the summer. I maybe can hit it one evening
this week, or Sat at the latest.

Will post my results.

 

Hi again Macx, (cheers for referring to me as a gentleman, by the way :lol: )

Sorry to hear you're still having wiper woes. Don't loose heart, it's a bloody frustrating system to fix...
Did I send you my own diagram of the system? I drew it out because the one in the shop manual is rubbish. If I haven't already sent it, it might help you visualise things a bit better...

I have to say, by the sound of your observations, that it seems like something ain't right with your motor - I know you probably don't want to hear that if its a new one, but I can't see where else the problem could be.

Just tell me how you're testing it.... Power into the middle wire (white) and ground to the top wire (pink) yeah??

quote:
The center/white wire on the plug is
the power in, so hook up power to that lug. Then ground
the lug for the purple wire (top lug, "high" speed) and
the motor should turn. Apparently the switch just grounds
the motor to make it work - there's power in via the white
wire at all times the key is on. If you add ground to the
gray/black wire, bottom lug, that should make it run in "lo"
Then removing the ground for the top lug should make it
park.


You're not quite on the nail there, I probably didn't explain it quite enough last time, sorry!

Yes, the switch does ground the motor to make it work (well actually it grounds a Relay inside the motor housing, which in turn makes the motor work. That way you don't end up with full motor current running thru the switch)

And yes, you have 12V "waiting" at the middle white wire with the key on.

BUT, it's the pink top wire you need to ground to make the motor run PERIOD, and then the speed of the motor depends on whether or not the grey bottom wire is grounded. I take it from what you've written that your interpretation was "ground top wire = high speed / ground bottom wire = low speed" so it's not quite like that.
Basically for the motor to run at all, you just need white 12v and pink grounded, then adding or removing the ground at the grey wire will switch between hi and lo.

Now I don't know if that will make any difference to what you've been doing, but it won't hurt to know exactly what to expect.

Quite simply, if you put 12 to the white pin and ground the pink pin, then that motor should run in high speed mode.
If it doesn't, then either it's a duff motor, or the main motor ground (the one that comes off the casing beneath the black plastic cover) isn't connected.
So check that ground wire as well. Good luck!



[Modified by theoUK, 11:55 AM 5/17/2004]

 

I always refer to some as a gentleman if they render
assistance :-)

I did understand your directions, if you read my post I wrote
"if you ADD ground" to the grey/black bottom wire - -
Course, that could have been written a little clearer also.

Anyways - while doing that I did have the pink park wire
hooked to the pass side of the cover and the single ground
below the cover was also hooked and had checked out good.

I'm still puzzled by the admonition on the sticker to not test
run the motor without everything hooked up as it reportedly
can cause reverse polarity and jam the motor.

It must be the relay inside the motor that's clicking when I
test it - either the motor is jammed (sticker says it ran good
under factory test) or - - ??

When I posted a question in the C4 forum, another kind soul
answered saying that all the controls are inside the cover,
that it is quite reliable (significant!) but that it is also expensive
when it does go out (he didn't specify cost). Looking at ebay and
seeing a number of 84 - 86/87 wiper motors for sale on there,
it looks like the motor has a separate plug and is smaller in diameter
than ours, but the gearcase appears to have the same configuration
and mounting bolt pattern. One showed it without the cover on,
and both the case shape and the internals looked like ours. Would make some sense as I suppose they maybe took the existing design and upgraded it instead of starting over. The covers do look different - "deeper" and
with a different surface profile. One cover had an area broken away and
something looking like a control board showed thru the gap.

If one could somehow be assured the electronics inside the covers are
good, the 84-86 motor assemblies were going quite reasonable.

Also looked like a similar 3 prong plug on the cover, and a catalogue
revealed the switch to be very similar - basically just a different mounting
arrangement - so maybe it wouldn't be too great a leap to convert to
an 84-up motor and it might just even work with the C3 switch.

I'll see once I can get to the library and check out a decent diagram of
the 84's.

Oh, no, you didn't send me the diagram. I certainly agree the one in
the shop manual leaves a lot to be desired!

Thanks!

 

Sorry, I guess it was me that didn't understand your post! :bb It can be a bit hard to communicate via text alone, but I'm just making excuses now! :)

Ah, now there might be a bit more confusion here but you mention the "pink park wire" on the passenger side of the cover. By this you mean the single wire on it's own, that connects into the main loom at a black plastic connector, yeah?
Well, that wire isn't the park wire. You can in fact test the motor without that single wire connected. The sole purpose of that wire is to send a signal to the controller when the motor gear has done one revolution, so it's only actually important in delay mode (if your system worked, you can show this by putting it into delay and removing that single control wire - the wipers would just continue at low speed, because there would now be no "stop" signal from said wire.

As you know, the only two wires that are really important for checking the motor operation are the white live wire and the park relay ground wire which is the OTHER pink(ish) one that goes in the top of the three pin multiplug on the Drivers side. To be honest, the colours are so faded that these wires could have started life as purple, red or pink, but I think you can get the idea by their location just as much as their colour.
So you can hear the park relay clicking (by the way its called the park relay because it not only has a normal electric function like a regular relay, ie using the small current to switch a larger one, but also because it has a mechanical element that maintains the power thru it, even after the top pink wire has been un-grounded, until the motor has parked up)

The clicking relay is perhaps a sign that the motor is stuck somehow, but for a new one that's quite a surprise, isn't it?

One more thing to check, when you unscrew the top cover, there is one lower screw that goes through the little spade for the lower main ground connection. Behind that screw should also be a little (brown, i think on mine) wire that snakes out from inside the guts of the motor. So the spade and the brown wire's end ring are sandwiched onto the case by the screw. You might want to check that this little brown wire is in good contact with the ground, if you havn't already. That being disconnected would make the relay pop but the motor fail to turn.

finally, to test the motor by by-passing the park relay completely, take off the cover and look for a black and red wire going into the depths of the motor. This is the main feed to the motor. Stick 12V into this and make sure the case ground is good, and the motor should run at high speed. Once you've gone this deep, it starts to look like the motor's jammed or broekn, but I'm afraid any further diagnosis is beyond me with the motor internals.

Keep me posted!
Oh, I'll send you that diagram...
:cheers:

 

Oh, yes, we love confusion!

Thanks for the info on what I was calling the "park" wire -
I knew it had something to do with the delay, guess I
was getting delay and park confused there.

Man, I think you may have hit on something here! -
I don't remember seeing that little brown ground wire
inside the case that needs to ground to that screw that
holds the outside ground lug!

I'll definitely look for that - sounds like that might be
the whole problem - makes sense that the relay would
click but the motor wouldn't turn if the motor itself isn't
grounded.

I remember seeing more than 2 wires inside coming from
the motor and going to the area under the 3 prong plug
(relay area?) - I'll look for a brown wire and pull on it to
see if one end comes out with a ring on it.

I, too, thought it strange that a new and supposedly tested
motor wouldn't work - it could be just that simple.

Really appreciate the info!

I'll check that tonite and post my results.

Thanks!

 

Theo

It just dawned on me that when I took apart the old motor
I didn't see any brown wire with a ring under that screw.

When I drove the car home last fall, I ran into a couple
light rain showers. At first the wipers worked, then started
hesitating, then quite altogether.

When I took the wiper motor out and apart, it appeared
someone had been inside of it before - maybe they forgot
to reattach that brown wire and it was just laying inside
the housing - that might explain the intermittent working
as the car was going down the road - movements of the
car bringing that brown wire in/out of contact with the
case.

Well, I can hope! :D

 

That makes perfect sense, about the brown wire connecting intermittently. I'm trying to remember where exactly it comes out from, but it'll be somewhere near the park relay. I don't have access to the digital camera at the moment, or I could post a shot of mine for you. Anyway have a poke about in there and see what's what. On a recon. or new motor it may not even be a brown wire, but if you see a ring terminal with no home then you know you're onto something.
Fingers crossed!
:cheers:

 

Well, it was a nice thought while it lasted.

Checked both my old motor and my new one,
and both only have the 2 wires coming out of the
motor itself and going into the area under the
3 prong plug. No other wires, or ring terminals,
in sight anywhere, even looking under the plug.

Oh, well, throughout my life I've resigned myself
to the fact that either I've got the only one
ever made and nobody makes replacements,
or I end up with a problem child like this. :sad:

Thanks for trying.

Guess I'll send my new one back to Eckler's
and see what they say - hopefully they'll test
it and verify one way or another.

If the next one won't work then there's very
obviously something else wrong - prob'ly
that board. If that happens, I think I'll
give a go to swapping in an 84-86 self contained
motor with the board built in the cover
and adapting it to my switch. There's prob'ly
more than one person out there who could
benefit from somebody figuring that out, hey?

 

Mark, You have mail.