'80 911 SC Headlamp switch wiring question, OE part update with different/additional

1980SC_Coupe · 09-27-2009, 04:56 PM

My 1980 SC (87k mi) was born with headlight switch 911.613.029.01 DOT. Porsche's current replacement for this is 911.613.029.03 DOT. The replacement has different terminal #s and an additional terminal. I am looking for guidance in connecting the old wires to the new switch. Many terminal #s are the same, however there are variations. Terminal #30 has two spades on both switches; the original switch has three wires connected to the two spades (one is piggybacked). The three wires are (1) red, (2) pink, and (3) light red with white stripe (piggybacked). The new switch's additional terminal #58 (not 58A, 58R, or 58L) between #30 and #56, prevents piggybacking the light red with white stripe wire to the #30 terminal as it was on the OE #30 terminal. I have no idea what wire attaches to the new switch's #58 terminal, unless Porsche decided to give the piggybacked light red with white stripe wire its own connection. Additionally, the original switch's terminal "K" is replaced by terminal "N" on the new switch. I suspect this is old news to many of you, and would appreciate your guidance in bringing me up to date. Thank you.

Canada Kev · 09-27-2009, 06:00 PM

The switch will work just fine, I suspect, as long as there is nothing wrong with it. I believe that if you replace the wires on the same numbered terminal, it should work correctly.

The piggy backed terminals you refer to, I believe are just a double ended U-shaped male couplers. One end is inserted into the wire terminal and the other is open and available to insert into another female wire terminal. I suppose this could be continued forever, but in my experience is limited to only two or three for each switch terminal.

I had a bit of an issue with my light switch recently and posted some information and my experience here. I got a couple informative posts from others. Here is the link to that particular adventure.

Headlights not working properly?

I hope this info helps out.

1980SC_Coupe · 09-27-2009, 08:57 PM

Thanks for your reply. The problem is (1) the terminal numbers differ from the old switch to the new, and (2) the intrusion of terminal 58 on the new switch takes up the space where the piggybacked wire was attached to the 30 terminal, and there is no room on the other spade either. Current wiring is as delivered from factory. Any thoughts on an information source containing guidance on converting the old terminal numbers to the new ones?

Canada Kev · 09-28-2009, 06:04 AM

Perhaps all those wires currently on pin 30 don't need power at all times. Pin 58 has power when the switch is on either of the two positions other than off. If some of those on 30 don't need juice all the time, could you move them to 58?

1980SC_Coupe · 10-04-2009, 01:16 PM

Hi Kevin. Thanks for your thoughts. Appears as though the piggybacked to 30 terminal smaller red w/ white wire is from the headlight flasher so it probably would work on 58, but without the ability to flash headlights unless the switch was pulled out, so it really wouldn't work as originally designed as I understand it. Is this correct?

Canada Kev · 10-04-2009, 07:19 PM

Yes, I would agree with that. If it requires power, it won't get any off of pin 58 unless the switch is in either of the two on positions.

It seems odd that your new switch doesn't have enough pins. When I replaced mine it was with the .03 and I had enough. I also have an older switch (possibly an .01), and thought it had less pins...

BTW, a pic is supposedly worth a bunch of words...

1980SC_Coupe · 10-11-2009, 09:02 PM

Solution was to extend one of the #30 terminals with a connector and to cover the unneeded #58 terminal, per photo. Heat shrink tubing was used to prevent unwanted contact. Terminal 58 is no longer in the way of #30's piggybacked wires. Original switch's terminal K was wired to new switch's terminal N. Newly installed updated switch functions as original.