HELP!! Turn Signal and/or Flasher Problem

[David E. Clark]

I hope someone out there can help. This one has me stumped! It concerns the turn signals and flasher in my 1973 911E.

My right turn signal works correctly but the left is VERY dim (both front and rear) then the fuse blows within five seconds. Using the flasher causes the fuse to blow as well. If I pull the flasher relay all the lights function correctly (same intensity/brightness). With the ignition OFF, and the turn signal turned on, the correct parking light stays on without flashing (as it is supposed to according to the owner's manual). All the bulbs are good (all lights work).

I have followed the wiring diagram from the factory manual (for hours) and confirmed that everything is hooked up correctly -- as best as I can determine. I cleaned and checked the grounds for all four parking/turn signal assemblies. I checked the under dash grounds and all seemed correct. I replaced the flasher relay and turn signal switch. All without success!

I figure I’m missing a ground somewhere or I have some wires crossed. It’s possible I crossed some wires when I replaced the turn signal switch but I was pretty careful and I marked each wire. Would crossed wires cause the problems I describe yet still allow all lights to work correctly -- except when flashing?

I know this is stupid but I’ll confess because it might give someone a clue. I put a 25 amp fuse in #2 instead of the 16 amp that kept blowing and the flasher relay melted -- melted a hole right through the plastic cover!!! So, my crossed wire/ground problem -- or whatever my problem is -- is pretty severe!!!!

PLEASE HELP. My car needs to be inspected and it won’t pass without turn signals!

P.S. I changed over to one odyssey battery just before experiencing these problems but I can't see how that is related.

As always -- Thanks in advance.

[David E. Clark]

I've been at this all day with no success. Someone, anyone, PLEASE HELP!!!

[Allenk]

I read your problem. I have no experience with this specific problem but have an interest since I'm in a project with all lighting disassembled. I've had a number of old vehicles and trailers and have had to chase e-problems. I would suggest a couple ways to attack. First label the wires and disconnect. systematically reconnect until the problem shows up. Or, put a meter to each circuit checking voltage. If you have short which I suspect you do, the voltage will be low.

[RoninLB]

Was it operating BEFORE you changed parts.. if yes it sounds like a hot is shorting ...............Ron

[Allenk]

Just another note, I had a Chevy truck with a very similar problem and a (+) wire had been chaffed and the wire was shorting against the rusty chasis. Interestly, it was only a problem in wet weather when the moisture helped conduct.

And don't over fuse it's not worth the potential problems.

[filou]

I would divide the test into 2 parts. First, disconnect ONLY the wires going from relay contacts to lightbulbs (the wires that energized the bulbs). If it does the same thing, you problem could be into the power supply of relay. If it is the case, check one wire at the time for power supply of relay. Look for shorts to ground and hot (+) with ohmeter after disconnecting batteries first.
Good luck, Filou.

[bigchillcar]

The flasher relay melted...have you gotten a look at the socket it plugged into? It's not easy to get to, but if enough current passed into the relay to melt it, the wiring leading up to the relay socket could be damaged.
Ryan