73S - elecrical lighting gremlins...need some counsel please

[mac73s]

In nearing completion of the restoration on my 73S, I find that I am chasing - so far unsuccessfully - some malfunctions in the turn signal and headlamp arena. During the restoration, all lamps were removed with their internals cleaned, the solid brown wire grounds from the harnesses are clean and bright and connected to equally clean/good grounds in their original positions, and the fuse terminal blocks are tight and clean with all new fuses. I am wondering if there is a common piece to the below malfunctions, i.e. signal flasher relay, headlamp flasher relay, and or turn signal stalk/assembly (or even main light switch?). Thank you all for anything you can point me to.

Both turn signal lamp indicators on the tach flash in unison when either left or right signal is used, yet when the turn signal lever is first activated, there is a momentary flash in of the lamp on the tach in the correct position, then immediately both lamps light

The headlamp flasher feature does not operate when the level is pulled back.

Switching from low to hi beams makes one headlamp dim

Only one (the taller of the two) filaments work on the turn signal bulbs (both sides) - meaning the same filament glows (in the parking light and flash mode)without the other one 'lighting'

Both front signal bulbs are dim (the right side more so, and when I jumped an additional ground to the right side housing the lamp intensity then matched that of the left side but they still seem dim compared to the rear lamp parking lights.

The right rear turn signal bulb will stay glowing (but very, very dim) after the turn signal is cancelled. All other aspects of the rear lamps are working perfectly, i.e. brake lights, reverse lamps, and the left side turn indicator.

[304065]

Did you disconnect the lamps from the harness, I assume the answer is YES

What part number on the flasher relay, can you post a photo
Also photo of fuse box

You have five different problems so you have to start with the basics and solve them one at a time for diagnosis to make sense

[mac73s]

Did you disconnect the lamps from the harness, I assume the answer is YES

What part number on the flasher relay, can you post a photo
Also photo of fuse box

You have five different problems so you have to start with the basics and solve them one at a time for diagnosis to make sense

Thank you for your reply. I will pull the flasher tonight and photo it and the fuse box. Yes, I did disconnect the lamps from the harness and cleaned the connectors and the surfaces of the bulb contact prongs. In looking at a previous posting with someone who had similar issues (that you helped immensely with), I realized that I did NOT clean the bulb holders (there was nothing obvious in the way or dirt or corrosion), but realizing now that these receptacles are where the bulbs get their ground, I will go back and carefully clean each receptacle with a scotch pad or wire brush if for no other reason to 'begin at the beginning' as you urge. More to come....thank you!

[304065]

Mac, where I was going with it was, are you certain you got the wires back on in the right order? Are you certain the wires were on in the right order before you took it apart?

What are the part numbers of the bulbs you have installed? The double blinker thing is absolutely a function of the wrong bulb or a defective bulb.

[mac73s]

Mac, where I was going with it was, are you certain you got the wires back on in the right order? Are you certain the wires were on in the right order before you took it apart?

What are the part numbers of the bulbs you have installed? The double blinker thing is absolutely a function of the wrong bulb or a defective bulb.

Here my homework photos that you asked for. Re the removal and reconnection of the lamp wiring, I did make a diagram of the location of where the wires were connected and hopefully re-installed them correctly - but in saying correctly - I mean as I found them so who knows. I plan to remove all the signal units and go through them again to eliminate any causes there. As to bulbs, I am using 1895 small bulbs at the corner markers which seem to operate just fine, and then 1073s where it calls for dual filament bulbs and 1034s for single. I am getting that information from the original owners manual, but did note that they call for front signal bulbs to be 1034s, but obviously incorrect as the bulb socket has two prongs for a double. All bulbs are new and I've tried several - either Phillips or Wagner but of course made now in China. Bulb tips have a small amount of dialectric grease. I did note that the 'C' terminal on the back of the flasher relay looks very dark compared to the others (should be evident in the photo), and such is the connection to the blue/white tracer wire that goes directly to a center location of the tach for the right/left indicators. Thank you for your interest and help. For $19.00 I have a new flasher relay from PORSCHE on its way.

P.S. ONE UPDATE....when I fiddled with the turn signal stalk to night operated it fore and aft to switch between hi and low beams, I can get both lamps to come to hi beams if I find just the right point, so that piece evidently has issues.

[edmayo]

You've had so much apart that there could be a myriad of problems. You'll have to start with a wiring diagram, meter, and patience. Disconnect the batteries, and then verify each circuit one at a time from the fuse box to the correct bulb socket and wire color. You will take one light unit at a time, and if necessary use jumper leads and power each circuit according to the wiring diagram and see if the bulb for that function works, out of the car if necessary. A bad turn signal relay can cause both lights to come on, I've also seen the new chinese copy light units to have doulble filament bulbs in single filament sockets,,,,out of the box brand new!! Are your light units original or repros?

[mac73s]

You've had so much apart that there could be a myriad of problems. You'll have to start with a wiring diagram, meter, and patience. Disconnect the batteries, and then verify each circuit one at a time from the fuse box to the correct bulb socket and wire color. You will take one light unit at a time, and if necessary use jumper leads and power each circuit according to the wiring diagram and see if the bulb for that function works, out of the car if necessary. A bad turn signal relay can cause both lights to come on, I've also seen the new chinese copy light units to have doulble filament bulbs in single filament sockets,,,,out of the box brand new!! Are your light units original or repros?

Ed - thank you for sharing your thoughts. The light units are original to the car and I will be taking them out to confirm the wiring. I have two poster-size enlargements of the wiring diagram and have found it most helpful...will put it to work again this weekend. Re your suggestion to disconnect the batteries and then test each fuse to the correct bulb socket, can you please expand on that...meaning exactly what the process is with a meter, i.e. what are the connection points with the meter and what readings am I looking for. While I'm a pretty good wrench and body/paint guy, I suffer a deficiency in all that is automotive electrics.

[ESully]

There are a few threads on the headlight high, low beam problems. Switch often has a problem with the contacts.
http://forums.pelicanparts.com/porsc...-pictures.html

There are also issues with the headlights where a set of relays are used to lighten the load on the contacts.
http://forums.pelicanparts.com/porsc...rly-911-a.html

[mac73s]

There are a few threads on the headlight high, low beam problems. Switch often has a problem with the contacts.
http://forums.pelicanparts.com/porsc...-pictures.html

There are also issues with the headlights where a set of relays are used to lighten the load on the contacts.
http://forums.pelicanparts.com/porsc...rly-911-a.html

E Sully - thank you for the links...all great information!

[RSTarga]

I recommend you clean the dielectric grease off with a solvent and use WD40 instead. Dielectric grease is meant to prevent electric current not aid in its transmission. I learned the hard way. Its fine on distributor boots to prevent leakage.