69 Wiper Motor Question

[t6dpilot]

I just removed my wiper motor to test its operation. Hooked up the correct power wires and only got the motor to run in the second (middle) speed selection. Yes, all the correct wires have the proper voltage to them when the wiper stalk is in low, medium, and high speeds. I also tested it straight off of a power wire and got the same results.

If I interpreted the wiring diagram correctly, the wiper motor speeds are controlled through built in resistors in the motor. If the motor works on one speed (the middle one), then the motor itself should be fine (I do have an electrical industry background). The only thing that I can think of that would cause it not to work in the other two speeds is a faulty resistor or an open connection between the spade connector and the motor winding (resistor?).

Does anyone out there have any experience with this specific situation that could give me some guidance? I would prefer using this motor versus looking for a used (or new ) one. Your help is appreciated. Thanks.

[t6dpilot]

Bump for any help. Thanks.

[Early_S_Man]

Sounds like you will need to remove , disassemble, clean, and inspect the motor for wear and/or damage. At that point you can post pics or figure out yourself what needs to be done to remedy the situation.

[t6dpilot]

Warren,
Thanks. Motor is out and seems to be in good condition externally. I plan on doing just that, but was trying to see if anyone here had more intimate knowledge and could help me understand the problem a little better. I need to determine if the resistors are bad (or open), can they be replaced or is the motor junk as it sits?

[Grady Clay]

Scott,

Sorry I missed your post. Saw it on ElyS.

Here is the diagram that I emailed you only with just the
important wiper/washer circuits. I also include details of
the switch and motor circuits.

This is really going to tax my memory and I don’t have one
handy to look at.

The ’69 is a very transitional year for wiring and electrical
components. For most purposes (not MFI) there isn’t
significant difference between ’69 911T, 911E or 911S.

As you will see below, I have some questions about the
’69 only wiring diagram SL 33.

The first problem is the diagram groups three components
into (25) “Blinker, Dim, headlight flasher, wiper, washer
switch with horn button in steering wheel.” In fact there
are 2 ½ components. The headlight/turn signals are one
separate part, the wipers/washers are another separate
part. The horn is wired into the chassis via the washer/
wiper switch harness. A main ground stud terminal is nearby.

Each of these two switch harnesses are wired into the main
harness via two 6-prong circular connectors in the bulkhead
between the driver’s knees and the trunk area behind the
paper-board under the cowl on the left side.

The motor assembly has five wires; red which is fused power
and is not switched (even by the ignition), brown (ground),
blue, black/violet and black/yellow. For the wiper motor
assembly the red wire only serves to return the mechanism
to its “park” position. If there isn’t power to the blue,
black/violet and/or black/yellow wires, the wipers stop in
the park position.

The switch has two interrelated parts; wipers and washers.
The wiper switch has four positions; Off, I, II, and III. The
washer section has three positions; Off, 1 (where only the
washer pump operates) and 2 (where both the washer pump
and wipers operate).

My recollection of the motor circuitry is that there is one resistor
and two motor windings. In interpreting the wiring
diagram, the large black rectangles are motor windings and the
smaller outline (53e) is a resistor. Note that one motor winding
is in series with the motor armature (circle with “M”).

In analyzing the apparent operation of the switch from
the diagram lets look at the three controlling wires (the black
wire is to the washer pump):
Blue – gets power only on II.
Black/yellow – gets power on I, II, III but NOT 1 or 2.
Black/violate – Gets power on I, II, III and 2.

How I interpret this is (wiper – washer positions):
O – 0; Everything is Off and 0 (zero) for the washer.

O – 1; Just the washer operates via black (53c).

O – 2; The washer operates and the wiper gets power via black/violate (53) in high speed (III)..

I – 0; The wipers are on low speed with power to
black/violate (main power, 53) and to black/yellow (53b).
I see this winding operating in opposition to the main
winding) Since this winding is getting full power, it has
maximum retarding effect to the main winding (53).

II – 0; The wipers are on medium speed with power
to the main winding (53) and to the retarding winding via
the blue wire (53e). The problem with my theory is the
power isn’t interrupted to the black/yellow (53b). That
would prevent the resistor from having any effect. This
may be an error in the diagram.

III – 0: The wipers are on high with power to just
the main winding (53). The problem with my theory is the
washer interrupting switch (shown closed in the zero
position) allows current to the black/yellow (53b).

I – 1: Washers operate and the wipers remain on I
with power to both black/yellow (53) and black/yellow (53b).

II – 1; Washers operate and the wipers remain on
medium speed (II) with power to both black/violate (53)
and blue (53e).

III – 1; Washers operate and the wipers remain on
high speed (III) with power to only black/violate (53).

I – 2; Washers operate and wipers remain on low (I)
with power to both black/violate (53) and black/yellow (53b).
Note this is via the upper contact of the washer section of
the switch.

II – 2; Washers operate and wipers remain on medium
(II) with power to both black/violate (53) and blue (53e).
Note this is via the upper contact of the washer section of
the switch.

III – 2; Washers operate and wipers remain on High
(III) with power to only black/violate (53). Note that the
upper contact of the washer section of the switch is
interrupted by no (retarding) contact on the wiper switch.


So, when applying just power and ground to the wiper
assembly, the only way it will work is with power to black/
violate (53) and brown ground.


Here are the power situation with the interconnection
wires (red is possible error):

Black; 1, 2.
Black/violate; I, II, III, 2.
Black/yellow; I, II, III, NOT 1, NOT 2.
Blue; II.

"
"
© Dr. Ing. h.c. F. Porsche K.G.

"
"
© Dr. Ing. h.c. F. Porsche K.G.


"
"
© Dr. Ing. h.c. F. Porsche K.G.

Please let’s correct any faulty logic here. Scott, one thing
we need to confirm is if you have ’69 components.
Yet another is to have the wiring diagram accurately
reflect how the 911 was actually built.

I found the circuit for ’70 intermittent wiper option and
for ’74 and later. I would like to figure out how to install
the ’70 intermittent system on ’65-’69 911s.

Best,
Grady

[t6dpilot]

Grady,

Thank you for the detailed response. That pretty much fits with what I have found. I checked all the wires for power in the various stalk positions I, II, and III. They are powered correctly. I again checked to see if the motor worked using power directly from the battery. It did, but only with power to the middle spade connector (see pic below). When voltage is applied to the left or right spade connectors individually, the motor does not run.

Looking at the diagram that you sent me (thanks again - that has been hugely helpful!), the bl/y, blue, bl/v connections are shown in a "line." I assumed that is how they were depicted on the motor as well - three spade connectors in a line.




I connected the bl/y, blue, and bl/v wires on the three spade connectors that are in a line on the motor. The motor worked in the II position. I changed the bl/y and bl/v with the same result (blue still in the center).

I just went to test it again for the purposes of this thread (connected to the acutal wires instead of just a hot line). It worked in the II position only, then it just stopped. Damn! I can't figure that out... Motor must be toast, eh? Aarrgh, this is frustrating.

Thanks for your help.

[t6dpilot]

Grady,

I misspoke earlier. The motor does still work in the II position. When I was testing it, the wiper mechanism nuts tightened up against the motor/wiper mount and prevented the wiper assembly from moving.

That is another question that I have... How does the whole assembly PROPERLY attach to the chassis and motor mount so the wiper mechanism (nut on either side of the tube that the wiper mechanism mounts through/to) does not tighten against the mount. baffles me... do you tighten the nuts on either side of the wiper post going through the cowl? Mechanically, it does not make sense. you should have a bushing or something riding against the mount to keep the two nuts from rubbing/tightening.

Shoot, I don't know right now. I am tired and am not making sense. It is hard to explain via text. I need to post a picture and add arrows, but I don't have the energy and don't know how to do the arrow deal. I am done tonight... thanks.

[Grady Clay]

Scott,

Before we go farther, see if you can find labels for the terminals. They should be labeled 53, 53a, 53b and 53e. There is also a ground spade connection somewhere.

I think my theory is correct. I only see one resistor (the big white ceramic thing labeled 12Ù (twelve Ohms).) The other wires from the terminal board seem to go into the motor (for windings and armature?)

I’ll go to some local shops and get a range of wiper motors and assemblies. They may just be “mystery parts” not associated with any model. I can still use them to help identify what you have.

Please post an image of the wiper assembly. That may give clues.

Remember, I’m not convinced you have ’69 only parts until we can actually document the proper functions and components. We will just be flailing our arms in the wind if you have a ’70 switch, a '71 assembly and a ’72 motor or some other mis-match. They all look way too similar.

Best,
Grady

[t6dpilot]

OK Grady, I will post a photo of the wiper assembly and motor mount. I cannot get to that until Wednesday evening, so will post then (I knew you were going to ask for this, but was too tired to deal with it last night).

Referencing the first picture, the ground spade is below and to the right of the three spades. The power (red) I am assuming is just above the center spade connector and is attached to the resistor. I assumed the other three were the speed connections - bl/y, blue, bl/v - but now I am certain that I am incorrect in that assumption. Looking at the wiring dia. again, the blue wire is the one connected directly to the resistor and the other end of the resistor connects in parallel to the motor winding. You can see in my second photo that the spade farthest to the right (looking from the top) has the resistor connected to it, as well as, a second wire going into the motor. One would assume that it is going to the winding as depicted in the dia.

So, I am going to theorize that the connections so far are:
_ (blue)

_ _ _ (black/yellow, ?, ?)

_ (brown)

I just need to ID which of the two remaining spades connect to black/violet and red. I will take another photo of the motor with the resistor mounting plate removed. Maybe we can ID the spades more clearly with the ability to see the wires going into the motor. Again, I will not be able to do this until Wednesday late aft. or eve.

Thanks again Grady.

[t6dpilot]

OK, I think that I have figured this out and wondered if I can get second opinions. Please refer to my first wiper motor picture as it gives the best perspective.

First of all, we are assuming that the wiper motor has two windings, which provide two wiper speeds. The third speed, which I believe is the slowest speed, is achieved by applying a resistor to one of the windings (middle speed). So.... after much mental gymnastics, checking and rechecking, This is how I have determined how this motor must be connected.
_ (blue) It is connected only to the resistor

_ _ _ (bl/yel, bl/vio, red)

_ (brown)

I came up with the bl/yel, bl/vio, red theory because the first one is connected to the resistor and another wire going to the motor. The second connector goes directly to the motor and is speed III, I believe. The third (far right) connection must be the red by process of elimination and the fact that it too goes directly to the motor. Now, one might ask, "how do you know that the bl/vio and red are correctly determined as they both go to the motor and not through a resistor. Well, when I applied voltage to each spade connector, the middle one (bl/vio) is the only one that operated the motor.

Based on this, I think that I deciphered the puzzle. I just have to make all the connections to see if it works. I am now certain, based on how the motor is wired internally, that you cannot just apply voltage to each of the connectors and get speed I, II, III. Also, when applying 12V to the far right connector (red?), it sparks as if it is a direct short. What I need to do is to hook up the wires in the correct sequence listed above and keep my fingers crossed that the other motor winding is not burned out.

I will post voltage readings for each wire and each speed position later tonight. What do you guys think?

[t6dpilot]

OK, for those who have wiper motors with the spade connector configuration that I showed in the thread, my connections listed above are the correct ones. The wiper motor now works correctly, yeah!! Thanks to all that contributed and especially Grady for his always detailed analysis. It really is a good feeling to know absolutely nothing about a particular problem and through research, asking questions, and deductive reasoning, to be able to successfully solve a problem. Well, it also helps to have an electrical background and be able to read a schematic.

Hope this thread helps others.

[Fishcop]

This thread helped me enormously with a similar '69 wiring issue, only I had a later replacement wiper motor to get working - the one with the square plastic terminal.

I have the early (four wire + earth) wiring... you've got Black/Violet, Black/Yellow, Blue, Red, and Brown (with brown of course being earth)

I've replaced your old/failed wiper motor with a later one that has five wires in a white plastic square terminal numbered 53 53a 53b 53c and 53i and an earth pin.

We need to make four wires go into five terminals correctly. Go and get yourself a 5 pin change-over relay (sometimes called a 'flip-flop' relay). These are numbered, 85 86 87 87a and 30; importantly 87 is normally open and 87a is closed and the following wiring order lets the wipers self park without causing a switched ground and shorting the fuse. You'll also need some female double spade ends and wire. The wiring sequence is:

Brown to earth, Black/Yellow to 53, Black/Violet to 53i, and Blue to 53b, Red to 53a. Then you take the relay and earth 85, run a wire from 86 to the empty 53c terminal. Jump a wire off 53b (Blue) to 87 and jump a wire off 53a (Red) to 30 on the relay. Terminal 87a is not used.

What you'll get is working 3-speed wipers with self parking. You'll hear the relay trip every wipe which is preventing a short each time the wipers pass the motor's internal park terminals (which would otherwise short out the motor).

I hope this saves the next person from spending 3 weekends trying to sort the problem!!!

[Porboynz]

I have a late model wiper motor stored away in case my original 72 version ever fails. I think I'll drive in the rain with the wipers off from now on to make sure I never need it because this thread makes quantum physics sound like an easy option. I hope I never have to read it and understand it, but if I do, kudos to t6dpilot, Fishcop and Grady, your honorary doctorates are in the mail.

[hellblau82]

Thanks guys for this thread..I was scratching my head having only 3 spades plus a ground on my motor but it looks as though someone has removed the resistor looks like I'll have to break out the soldering iron

[hellblau82]

any thoughts anyone on connecting my 6pin wiring
Red white
Blue white
Green
Black yellow
Black violet
Brown

To the 5 pin older style motor like pictures above????
Do I not connect the green??
So much confusion!!!

[hellblau82]

[crashtest22]

I am sure this was resolved. but I was just looking for the connections on mine then remembered I took a picture.
Here it is looking at it from the top. 1969 911E Chassis
Just hooked it back up like the pic and all works as it should

[hot66]

Sorry to drag this thread up ... but trying to get to the bottom of a problem with my 1973 Euro 2.4S

For some reason , every so often , usually at high revs/ speed the wipers will come on by themselves at a slower than usual sweep .... I pull on the washers ( as it’s inevitably a dry day ) play with the switch and they stop and then don’t do it again. I’ve had the switch off the car and cleaned and inspected it and all looks fine as it is a relatively simple mech.

Any suggestions on why this might be happening ? Dodgy earth ? Or something in the motor?