Terminal 57 on headlight switch???

DUK · 07-14-2006, 07:44 PM

Tell me what the heck this is used for. There is continuity between term. 57 and 58a, only in the off and first (parking light) position. No continuity when in the 2nd position (headlight). There is also variable resistance between 57 and 58a in the off and first position. Doesn't seem right to me and according to the wiring diagram I have term. 57 goes to the headlight relay. Any ideas and/or help will be greatly appreciated. Thanx, Duke PS it's a 75S.

DUK · 07-15-2006, 05:28 AM

Sat. morning bump for help.

scottcip1562 · 07-15-2006, 06:00 AM

Check out Daniel Stern Lighting. Lots of good info there.

http://www.danielsternlighting.com/

Wil Ferch · 07:32 AM

First of all...there would be NO factory wiring diagram that would indicate it goes anywhere from the headlight switch to the headlight relay. Why? Because Porsche ( in their wisdom...) did not power the headlights thru a relay. So I'm confused with your statement.

These terminals were under discussion elsewhere ( I'll find the thread and repost later) where we intended to fuse the dash lights ( another failing from Porsche as delivered).

Ahh...here it is..maybe it'll give you more clues...dunno..

Dash lighting fuse installation

- Wil

DUK · 07-15-2006, 07:25 AM

Wil, not to argue, but the diagram in the pelican electrical diagram and the one in porsche workshop manual both show terminal 57 off the headlight switch going to terminal 86 on the headlight relay thru the connector 85 and the relay number is 50. I'm no electrical eng but I'd like to think I can read a simple diagram. Am I seeing things right or what? I've noticed some other questionable practices in their wiring, so I'm sure this won't be the last problem I run into. Thanx again, Duke

Wil Ferch · 07-15-2006, 07:42 AM

Admittedly I don't have the wiring diagram you mention in front of me as I write this but there has NEVER been a HEADLIGHT RELAY in the circuit as delivered from the factory in any Porsche built at least through the later 80's...maybe even later.

Let me clarify..... Specifically... I mean a relay that acts as a swtiching circuit, and pulls in another set of contacts that provides POWER to the headlights from yet ANOTHER circuit.

That's the problem we're all trying to fix. The problem of having full power amperage go through the dinky steering column switch which fails over time ( even with stock headlight power) and disrupts the hi/low function ( usually allows only hi).

Many of us have posted adding relays like the Sucro kit...to gain relay advantage that the car should have had from the beginning. This decreases (as I'm sure you know) the power load on the steering wheel switch to less than 1/100 ( or more) the amp draw it had before.

Likewise...my intent is not to be argumentative...but clarity. I'll gladly stand down if found wrong, so I too would like to know more about this as no Porsche that I know of had this.

I'd be interested to get comments from yet others....

Best,
- Wil

joefrantz · 07-15-2006, 07:53 AM

I've seen that relay on the wiring diagram too.

Warren explains here: Round Relay Behind Gauges

Joe

DUK · 07-15-2006, 07:56 AM

Ok, so I am seeing in the diagram what you are saying. The "headlight relay" is really just a switch over from low to high beams. I've already remedied this by putting two relays in the circuit. The first gets it's power directly from the battery and is triggered by the headlight on/off switch, which then triggers the second relay. The second relay sends power to the low beams and when triggered by the dimmer switch sends power to the high beams.

My main question still is the terminal 57, and why it shows resistance to terminal 58a? What am I missing?

Don Z. · 04:40 AM

Wild guess... as I went through something like this when my headlight switch started smoking, and I had to pull every wire before I could calmly write down which wire went where before the whole car became an inferno...

I think that perhaps that terminal is for our non-existent city lights. That is to say, that little bulb below the main bulb in the H4s that you could simply wire in with your parking lamps.

As I said, I'm just guessing... but it's the only thing that made sense to me at the time...

(edited because I can't spell "parallel" and I was called on it!)

donporfi · 07-15-2006, 01:48 PM

Don Z
You need to wire in parallel to the parking lights, not in series.

donporfi · 07-15-2006, 01:56 PM

In the diagram of an 85 Carrera terminal 57 goes with a white /green cable to the speedometer (side marker indicator).

RoninLB · 07-15-2006, 06:10 PM

P Workshop diagram

DUK · 07-16-2006, 07:02 AM

Thanx guys, Don I was wondering the same thing about a driving/parking light.
Ronin- that helps clear it up.

I simply omitted it as I'm am rewiring my whole car anyway. Man you should see my wiring diagram. Maybe some day I'll post it for a laugh. The post would have to be 30 pages long just to fit it.