71 911T electrical

[jayfrowe]

Just finishing complete restoration of my 53 years owned 911T. Left turn signals and left hazard lights not working. All other lights (head, parking, brake, license, gauges, interior, etc.) working fine. Relay clicking normally in all switch (turn and hazard) positions. Thanks for any help. JFR

[E Sully]

Here is an earlier thread on the subject. I made a couple of simplified diagrams of the system. A lot of times issues are due to poor ground connections.
71 turn signal function

[Tremelune]

It's probably the grounds, even if it doesn't seem like it would be the grounds. The lights on these cars are wired in strange ways, and sometimes switch on the negative post.

Lots of threads here. The real solution is to go around the car with an incandescent test light and just...see where the circuit breaks. It'll be the grounds in the housings, sometimes right at the bulbs.

[PeteKz]

^^ Most likely this. I have had to clean grounds at all the signal housings on my 1973 over the 30+ years I've owned it.

[jayfrowe]

Originally Posted by E Sully

Here is an earlier thread on the subject. I made a couple of simplified diagrams of the system. A lot of times issues are due to poor ground connections.
71 turn signal function

I don’t think it’s a grounding problem. Reasoning (which, of course, may be faulty): the bulb and socket in question is a two pole unit with one pole being the parking lite and the other the turn/emergency lite. Since the parking lite works normally doesn’t that suggest that the socket is properly grounded? In addition when I put an ammeter to her, and one lead properly grounded, I get a steady 12v from the parking pole and nothing from the turn/emer. pole. When checking the right side the parking lite pole works fine and I get a nice intermittent 12v from the turn/emer pole. Could the relay fail on just one side despite it clicking away nicely? But I have never understood electricity what with all those itsy-bitsy electrons running to and fro along wires at the speed of light.

[jayfrowe]

Don’t think it’s a grounding problem. Reasoning (which, of course, could be faulty): the bulb and socket in question is a two pole unit with one being the parking lites and the other the turn/emer lites. Since the parking lites work doesn’t that mean the socket is grounded properly? Also when I put an ammeter to her, and with one lead grounded (either to the socket or other metal part) the parking lite contact works fine but not the turn/emer contact. And when I check the right side I get a steady 12v from the parking contact and a nice intermediate 12v from the turn/emer contact. Is it possible that the relay could fail on just one side? It clicks like normal regardless of where I have the switches placed. But I guess I really don’t understand electricity what with all those itsy-bitsy electrons running to and fro along the wires at the speed of light.

[Tremelune]

I've found a grounding issue between the bulb and the bulb housing...the metal tab was only slightly shiny, when it needed to be very shiny! That said...it's not always the grounds.

If you wind up cleaning metal, it's a good idea to spray it with Corrosion X or even Fluid Film to prevent future oxidization.

[E Sully]

There can be a bit of internal cleaning needed on some housings. The grounding on my 73 housings was not very good, but I have seen later housings with improved grounds.

I did a bit of work on mine.

[Jeff Burger]

Did you use a test light or meter to check if the 12 V is getting to the tailight multi pin plug in the rear side of the engine compartment?