The motor case does not serve as a grounding connection, nor is it designed to carry any current at all.

There are two wires entering the motor, neither of which show continuity to the motor case.

Through the various relays and limit switches the polarity of the two motor wires is changed. A polarity change on a DC motor changes the direction of rotation for that motor.

Near the center of the diagram, BK denotes the grounding connection for the relays and for the motor.



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So here is the deal. Ignition switch works, dash headlight switch works, limit switches work, battery is charged, relay "clicks" but I'm not sure if that is a sign of working, .. the motor .. nada, zip, nothing .. no sound, no movement, no heating up even with the headlight switch on. It looks like I need to remove the motor (ugh) and test it. I may have a source of another one. Question: the headlight relay from Wilkinson is about $190 .. does anyone know of a less expensive alternative?
during the last checks, have you used the handwheel to position the buckets. the reason I asked, I am ASSUMING the motor is bush design and that maybe you burnt one of the commutator's teeth and by manually spinning it to a new tooth would allow it to start.

another test would be check the two leads of the motor for continuaty with the Ohm setting on your DVM. I checked my motor (that had't been spun in decades) and it showed 15 Ohms. after spinning it a little, the DVM became a "random Number generator Smiler " and showed about 20 to 30 ohms. A reading of infinity would indicate burnt away brush or tooth
The relay is just a dpdt 12v coil relay. This one is rated at 30 amps and sells for around $10.00 or so at ebay or amazon or many other places. You may need to add a jumper from one contact to the ground.


Another update. I pulled the motor/gear assembly and bench tested. It works just as designed. So my search continues. I tested the two limit switches. They show open normally and a small continuity resistance when clicked (closed) I always thought they opened when clicked .. but just the opposite. This now leaves the relay, the dash switch and the ignition switch as suspects.

Question: should the headlights come on when the headlight switch is fully turned on even with the ignition switch completely OFF? Mine do. I can see why the parking lights would come on but the headlights? If the answer is no then that might be a hint as to my problems. I'm looking more and more at the relay. The beat goes on.
Not sure I sure i want to admit my experiance today.

I tested my two switches and got your results...I was confussed, how could the circuit work. I was even using my high dollar Fluke.

This worried me all afternoon, coming back from an errand, I decide to verify. this time using a Radio Shack that I abused that was in trailer.

First check...same as yours. checked my meter auto setings, tested my leads for open/closed.

THEN, i got the expected
normally closed,
open when pressed.

I am sure I repeated this several time.

Maybe it was a meter setting

BTW...I quit work years ago when I was getting confussed alot

took a couple photos since I can forget....


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I played with my lights a little - not sure if this will help:

PS. When I say "Light Switch ON" I mean two detents - i.e. Headlights, not just parking lights. I also get two lights on in the instrumentation - one on the tach, and one on the speedo.

1. Ignition OFF / Light Switch ON: Parking lights are on - Headlights are down and ON, even thought the buckets are retracted.

2. Ignition ON / Light Switch ON: Headlights come up and the lights are ON as the bulbs are coming up.

3. Ignition ON / Light Switch OFF: Headlights OFF as soon as the switch goes to OFF, and then the lights retract.

4. Light switch OFF, then Ignition OFF (during retraction): Headlights freeze when the ignition switch is shut off.

JFB .. I'm no electrical genius .. just the opposite. I think that the limit switches are suppose to connect when clicked and open when unclicked. I think that the limit switch tells the relay to stop or start powering the motor. The motor circuit is not directly interrupted by the limit switch. There is a lot of current operating the motor and the limit switches seem much to fragile to accommodate 30 amps or whatever they draw. But I could be wrong. Smiler

I may replace the limit switches just because of their age but I really think the relay is the culprit.

Rocky, thanks for the light tests .. very informative. For those with high powered headlights, if they were going to just park and hit the parking lights but accidentally pushed the rocker switch to the second position, those retracted headlights are going to fry the bucket covers. Very odd design.

I sense a headlight at the end of the tunnel.
I still recomend making a lamp to plug into the motor's two connectors to help you see what is going on without the chance of damaging the motor.

Using aux relays to reduce the current through the switches is possible, but have you seen those two realys somewhere. Also, with out making a logic diagram to verify, using normally open for aux relays would mean those two relays need to be hot when the motor is NOT running....not a good design.

Redoing the factory wiring so that the headlights do not light until the buckets are opening was on my wish list
My headlight issue is approaching a finale. While under the passenger's side dash looking for the proper relay (pre-L location) I found that the relay panel is secured by two wing nuts and can be dropped down for better access (a discovery for me). Protruding down from that panel is a long(4 or 5 inches)threaded rod also with a wing nut but it does not secure anything .. it's just there. Question: is there suppose to be a panel or kick plate that that long rod secures? What is it's purpose. I've owned 3518 since Jan. 1973 and have never removed anything down there (that I can recall .. but I'm older).
I suspect your relay board is missing it’s perforated cover, as shown in this photo.

FYI, with some rearranging of the components and careful routing of the existing wiring, I relocated my panel on 2511 to a much more user friendly location.



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WOW ... I certainly would have remembered that component. I bought the car from a Porsche dealer and there was one owner before me, and then only for a few months. I wonder where that damn thing went? I suppose those are NLA. Thanks for the info.
There should be plenty available as many have redone their wiring (including me) and did away with that whole set of relays. I probably have it around here somewhere as I don't throw any Pantera parts away. ZONKEY is an early car (1549) and it's possible it's a different size. I seem to remember that the holes are a lot smaller.
I should probably measure the relay panel to get an idea of how big that missing perforated cover should be. My car is 3518 so I don't know where that sits in the pantheon of relay covers. I've got my checkbook at the ready if someone has a spare.
My headlight issue is no longer. After removing and checking out all the electrical and mechanical components of the headlight system, I reassembled and TAA DAA .. it works as designed. No repair/replacement of any parts. The only expense is bandages for the fingers and arm cuts from working in tight quarters with sharp edges.

The questions now are: why did it happen and how did it go away? As best as I can figure there was binding between the small drive gear and the sector gear on the headlight bucket shaft. The motor mounting plate is slotted for positioning. Gear engagement is critical. When I reworked things 3 years ago I didn't run the lights up and down manually to verify proper gear engagement .. I did this time.

So it works and the above is the best explanation I can come up with. The motor overheating was due to having to work very hard to raise the buckets. If its not that .. I got nothing. But it WORKS

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