Left Turn singal issue... stumped
 

I have a 912 with a 2.7 in it, shouldn't matter because it's still a 12v.

My left turn signal doesn't work properly. The front light flickers but the rear light does not.

1. I put a test light into the connector and it flashes, so I know that, it's working correctly. I then switch the rear bulb socket to the front to test to see if the rear bulb socket is working correctly, and it is...

The voltage jumps from 3v to 6v from the connector..

Please help me, because I am completely stumped.

In my 81 SC there is a rubber socket way in the back of the engine compartment on the driver's side that feeds the tail lights..

You can unplug the male connector from it. It only fits in the female socket one way.

On my car the female port in the 10:00 position is the blinker feed. Isolate the male prong that corresponds to the female port and check voltage with blinker on. If voltage appears way better than 3v and 6V the problem is downstream of the female port. Guessing a poor ground to the light body.

However, you may simply need to flex the spring contact tab a little closer to the light bulb but the voltage numbers appear odd so thinking something inside the light.

Thanks Bob, I will check that out.

verify your turn signal housings electrical condition. My 73.5 had bizarre turn signal issues when trying to restore this car. It turns out the internal sealant within the housings were causing an intermittent short. It took quite a bit of effort to track down and recondition the sockets and wiring.

let me get this straight.
the left front bulb works correctly
if you put a test light into the socket for the rear, it works correctly.
here is where i am confused. are you actually moving the "socket" form the rear to the front or just the bulb?

where are you grounding the test light?
if you are using a seperate ground for the test light than what the bulb is using (as in the ground thru the socket and wiring) then i would look at the ground side of the socket and wiring frmo the light housing.

very good on using the test light.

you can connect the testlight to 12v at the relay panel and probe the ground side of circuit for the rear bulb. try it on the front first using the battery to see how it works. the TL should be as bright at the rear as it is at the front.

+1. Has to be the bulb, I think. However, he did say socket, which is the female receptacle.

The female receptacle. Heh heh.

I am moving the socket and the same bulb, to a different housing and they work together, that's how I know that the socket and bulb are good.


I have grounded the light on the housing and also the body of the car.

Maybe I should make a youtube video...

so...

I put a voltage meter to the ground wire that attaches to the housing its self and the hot spade connector. The voltage jumps up and down from 3v to 7v. As soon as I attach the test light to both the ground and the hot wire the voltage drops to 0.

On a side note, I have been able to get it to work correctly until it gets screwed in tightly...

Thoughts?

99% of the time its a poor earth connection or a corroded bulb mount which is the same thing. Take a battery jumper cable and attach one clamp to a good earth and clamp the other end to your light housing and try again.

After making sure all grounds were good, I did the following to correct good bulbs not working.
Drop of solder on bulb contact(s) and 3 drops of solder around the metal base. Shave down with a file for a good tight fit. Now I have reliable turn signals for the first time in many years. A big thank you to JimK.
As an aside, I also, while in there, replaced the brake and backup bulbs with led units. Huge improvement. Again, thanks to JimK.