Headlight Switch Wiring Help!

[waazzupdude]

Dear fellow Porsche men and women,

Sorry I am kind of new to this forum. So forgive me if I do not follow conventions of the forum properly.

I have a 1983 Porsche 911sc ROW

When I took out the headlight switch, I did not take a picture of the wires thinking I could do a one to one replacement, but for some reason, many functions were not working. I took all the wires out and tried to put them back in according to the following picture

What I dont understand is on my switch 75 does not have a double it only has one pin.

I have the following wires,

From somewhere else in the car (maybe even ignition not sure)
1.white/green
2.red
3.gray piggyback to another gray
4.red/white
5. black/blue piggybacked to a short black blue cable white a white connector
6. red/gray piggybacked to another red/gray from turn signal

Then from the turn signal stalk I have:
7. white/black piggybacked with a white/black from car
8. red/white
9. black/white
10. gray wire with black head connector
11. gray wire with white connector

From ignition:
12. black from ignition switch


I followed my wiring exactly the same as the switch from the earlier picture except for 75 I just put red/white by itself. I got no juice in anything. Can someone send me a picture of their headlight switch from all corners so I can get an idea of which color wires go where.

This is the picture of my headlight switch. 91161302901

[waazzupdude]

sorry, I am not sure if photos posted.

this is the switch I followed


This is my switch.

[Canada Kev]

A few years back, I had a headlight challenge where a previous owner had a defective switch in that the headlights would not work. The PO removed the switch and transferred the headlight wire to a different terminal (license plate in my case) that was powered. This meant that the headlights were always on in any switch position other than OFF. So when I wanted just the running lights ON, the headlights were also ON.

Anyway, in my trouble shooting, I drew up this matrix listing the terminal, and its power state in each of the three positions of the switch (OFF, running and headlight).

You might find this useful in your particular challenge. Don't freak out, it's not a big deal and there's only about a half dozen wires to worry about and you won't blow up your car by plugging them into the wrong spot on the switch. Unfortunately, I don't know any of the wire colours other than the fog lights (probably grey).

This diagram will tell you which terminal pin should be powered at the differing positions of the switch. If you put your suspected headlight wire on pin 56 and they don't work they way they're supposed to, well, that's likely not the actual headlight wire. But then if your LEFT running lights illuminate only when you pull the switch out all the way, that wire is probably for the LEFT corner lights. And so on, you get the idea...

Before you start moving wire around, I'd baseline your switch to ensure all positions and pins operate how you expect them to. And when you for sure figure something out, label the wire.

Also, for doubling up wires on the terminals, I had some removable U-shaped pieces of metal that would bridge two wire ends to fit both of them onto a single switch terminal.




IMPORTANT NOTE FOR PIN 57: on the matrix diagram, I have pin 57 (dashboard parking light indicator the speedo) showing voltage with the ignition on with the switch at the first position. This is INCORRECT. It should be in the next spot with ignition off and switch in position 2 and should be swapped. That pin is only powered with the ignition OFF and the switch in any ON position. Sorry for any confusion.

My thread discussing my own issue:

Headlights not working properly?

[waazzupdude]

Canada Kev thank you so much! Yes I did read your post. I am glad you are still on the forums. I had a few questions about your method. How exactly do we test each pin. Do we put a wire on one of the pins and go through each position to see if we get desired effect? Or does your test involve using a multimeter. Also what does headlight ckt mean. And how does your method account for the different turn signal stalk positions.

Just to update you all on my progress, I plugged my wires in as best I could to match 1982 wiring diagram. One of my problem is that when the switch is at position 2, the right brake light comes on and the left turn signal light comes on. When its at position 2 or 1, the high beam and low beam is always on. Sometimes when I push the turn signal stalk halfway forward (flash to pass), the high beam shuts off. It's an electrical nightmare.

Also I would still appreciate if anyone could take a nice picture of there headlight switch for the forum, I think that would be excellent.

Cheers!

[86 911 Targa]

Originally Posted by waazzupdude

sorry, I am not sure if photos posted.

this is the switch I followed


This is my switch.

I took/posted the blue pic when I did our '86.

Gerry

[Canada Kev]

Headlight ckt = headlight circuit, also the pin on the switch that transmits current to turn on your headlights. This is for high beam, low beam, left and right; whatever you have for headlights comes off this single terminal pin on the switch.

Just to be clear, you were initially asking about the headlight switch. Did you also change out your signal stalk? If you did, that complicates matters. If it was just the headlight switch, that's pretty easy to figure out. At this point I'll just assume it's just your headlight switch that you've replaced.

First, you need to baseline test your switch using a test light or multimeter. Ground the test light or negative lead on the meter. With the HL switch and ignition switch both in the complete OFF position, test each pin to determine when it is energized and record your results. Do the same with the ignition switch on the RUN position. Then first notch on switch and ignition OFF. Continue through until you test every position and every pin on the switch. That's the first step complete. Hopefully it lines up with my diagram, except for pin #57 for which I made a correction note above.

Because you don't know what any of the wires are for, you can take a single wire and connect it to one of the pins on the switch. Personally, I'd start with any I thought I might know, like the fog light which is likely the grey wire. If you use the pin that's always hot (should be pin #30), you don't have to mess with the ignition switch or turn on the HL switch. Just be sure you don't turn on the HL switch by accident and mess up your testing. Once you have that wire plugged in, go around your car and see what turned on. Then label the wire. Just remember some circuits have a secondary switch that needs to be activated, like the fog lights. In that case, take the wire for the fogs, plug it into the HL switch on a live pin and then turn on the fog light switch. Your fogs should turn on. If some other light turns on, that's not your fog light wire; it's the wire for that other light. Go through all your wires one at a time until every one is labelled for what it is.

Now you can put all your wires on the switch in their proper locations. You'll have to use some common sense here because the switch isn't labelled for function. You already know that your headlights should only illuminate when the ignition and the switch is all the way on to the second detent. If your data from baselining your switch line up with mine above, that corresponds to pin #56. If you put it on the pin marked N, your headlights would be on whenever the switch was in the first or second detent and ignition ON, because that pin is energized when those two conditions are met. If you want your headlights on whenever the car is running, put the wire on pin #75 which is energized whenever the key is in the ON position. I'd recommend setting it up the way it was from the factory initially.

Only after you're satisfied all is good, should you begin to customize and move things about to meet your personal requirements. For example, the fog light wire is positioned from the factory to be connected to pin #56 so they operate only when the headlights are turned on. I thought that was kind of dumb and rather useless, so I moved mine to pin #75 so they would work with the HL switch in any position and ignition ON but would turn off automatically with the ignition switch off. This way I can use them as daytime running lights but would not stay on when I forget to turn the fog light switch off when I leave the car. But I can still turn them off anytime I want to using the fog switch. Like when I'm sneaking home at midnight all liquored up from a night out with the boys and don't want to wake the girlfriend. Holy, tough crowd. I'd never do that. I already know that girls nights typically last far later than midnight...

[waazzupdude]

Dear Canada Kev,

Thank you so much for your explanation. I appreciate all the time in writing your post. I have yet still more questions. I understand holding the lead from multimeter to ground. But do i use the red probe on the pins coming from the headlight switch or the wires going to it. And how is the headlight switch being energized.

Also i did change the headlight stalk at the same time. Hence all the confusion im experiencing

I also have two red/white wires which also confuses me.

[Canada Kev]

I can't help much with the signal stalk as I've no experience with one of those. Perhaps if you get the headlight stuff sorted, it might become more clear. And some of the wire there should have the same colours as what you have going to the back side of the HL switch. Also, some wires from the HL switch will go directly to the end user light such as the fog lights (what's with this guy and his damn fog lights...?).

I hope that when you are all done with this, you're going to install headlight relays to protect the HL switch and signal stalk in the future. In the stock condition, all the current for the headlights travels through those two items. JWest has an inexpensive, simple kit. It's worth every penny.

You should be metering the HL switch. All the electricity for most of the lighting of your car travels through the HL switch. The switch is energized by the battery through the fuse panel in the trunk.

Think of the electrical system as a river flowing from the alternator and battery, through the fuse panel where it splits into several tributaries with one of those going to the headlight switch and then splitting again with some continuing to the turn signal stalk/switch and then on to headlights (and other lights).

As a side note, the headlight relay will detour the main flow of the current from the battery directly to the lights, bypassing almost all of that wiring back and forth to the HL switch and signal stalk. It gives you brighter lights due to less resistance of all that wire and less damage to the switches.

So at the HL switch, with no wires connected, the electricity stops at the switch. It's a logical flow - disconnect the wire and the electricity stops. It's still there at the switch, waiting to move along, but it can't until there is a path of travel, ie. wires.

When I suggested to baseline test the HL switch, it was to see what each of the terminal pins was offering for electricity and under what condition with the HL switch and ignition switch position. You don't need to know how much electricity there is (will be about 12 VDC except possibly pin #58a), just IF it's there - that's why a test light would also work. That way you could determine if when you plugged wires into the switch the lights were operating as expected. The reason I stared that thread I referenced above is because I thought I had a problem I couldn't explain. It turned out my switch was defective but I didn't know that when I began because I hadn't tested it thoroughly. I made an assumption that created weirdness in my problem.

Again, using my example of the fog light wire, if you plug it into pin 56 and it doesn't work when the headlight switch is turned to the second detent with the ignition ON and the fog light switch is ON, something AFTER the HL switch is messed up. You know this because you already tested every single pin on the HL switch in every available operating condition (switch position and ignition) so you know how it should act.

Hints - use with a bit of common sense.
- You can't make assumptions. You can only test to know for sure. Don't guess.
- Change one thing at a time if you're not sure. Hell, sometimes even if you ARE sure.
- Write stuff down.
- Label. Use plain English and not number codes as if you transpose any from your cheat sheet, weird things could happen.

DC electricity isn't difficult. Sometimes people get freaked out by it. It's not magic. It flows from one point to another. Like a river. It doesn't appear somewhere if it wasn't led there by a wire or other conductor. Take it one step at a time. Take your time. Get your Spock on and wrangle the logic from your brain. You got this.

If you're super stuck and can't work through it, drop me a PM and I'll give you my phone number so I can walk you through what I can verbally.

[waazzupdude]

I have figured out largely except that instrument lights not work. All of my tail light housing bulbs are also loose. So I am sorting those out. Once I figure it out, I will upload the wiring that worked in my car

[waazzupdude]

This is the wiring that worked for my car hope it helps anyone else in the future. 1983 Porsche 911SC.

[hierogk]

Old thread - similar problem

My 1984 911 needs state inspection and the light switch appears to be no bueno. I haven't driven it at night in a while so I just found out.

Symptoms: light switch terminal 56 is only hot and the headlights only come on when the light switch is in position 1 and the ignition is switched on. (i'm calling light switch position 0 off, position 1 intermediate and position 2 fully out.) They are off in light switch positions 0 and 2 with the ignition switched on and they are off in all light switch positions with the ignition switched off (and there is no voltage at terminal 56 at these times). Same scenario with the license plate lights (terminal K) and the indicator light in the speedometer (terminal 57). Oddly, the dash lights (terminal 58a) get power with the ignition switched on and the light switch in positions 0 and 1, but not 2.

On the other hand, the parking lights work only on light switch position 2 - key on or off. So, I get headlights but no parking lights on light switch position 1 (with the key on only) and I get parking lights but no headlights with light switch in position 2 (key on or off). I don't think the inspector will be too happy with that.

Can anyone on this list help me see what I may be missing before I lay out $550 for a new one (and probably find out I misdiagnosed the problem)?

Thanks,

Bill