Test for flasher relay

[speedo]

Just got a car running after 25 years. Headlights and brakes work, but turns...not so much. Have pulled all the fender plugs and re-installed. I have extra flasher relays and tried replacements but nothing. I am wondering if after 25 years my relays are bad? PO installed a hideous alarm system as well as a stereo and I ripped all that out. Hoping that none of that affected the "corner" wiring. Haven't tested the voltage at the turn signals yet...wondering if my problem is the relay itself.
I am used to the clicking sound. Also wonder if it could be the yoke on the steering column? All the fuses seem to me ok. I pulled the bulbs on the corners and they are all ok.

[NeunElf]

You haven't given enough information for me to diagnose anything.

My first suggestion (this worked on my 356A): spray some good contact cleaner into the turn signal switch. On a 356A it's easy to see the turn signal contacts, the're maybe 1 mm diameter and on delicate little springy levers. I wouldn't want to clean them via any physical means but sprays should be safe. I've seen Würth Contact OL miraculously revive my 356A's turn signals. If you can't find the Würth stuff at least get something from an electronics store as opposed to your local auto parts place.


My second suggestion: Test the relays.

Base of Stoddard's Replacement Flasher


Schematic from Turn Signal (Indicator) Flashers and 4-Way Hazards (for VWs)

C = Turn signals (turn signal flasher)--Indicator lamp 1
49 = Flasher relay (pulse generator) Input
49a = Flasher relay (pulse generator) Output
31 = Return line from battery negative terminal or ground (direct)

So, if you get some jumper wires and connect terminal 31 to ground and terminal 49 to a 12 V battery and terminal 49a to a light bulb (like the one in your turn signal housing) or ¼ to ½ Ω resistor you should get clicking sounds if the flasher relay's good.

My third suggestion: get out the voltmeter and check where you do and do not have 12 volts when you try the turn signals. If you don't have a wiring diagram, you can download many of the diagrams from the shop manuals from Early911nz downloads, members.rennlist.com/911pcars, or electric_wiring_diagram_1972.pdf.

[72t4tom]

the alarm system may have been connected to flasher to blink corner lights as well as horn/siren

[71gold]

Also check that any of the grounds you may have disrupted be sure they are absolutely solidly connected .
Also clean these posts at body .
The flasher unit is know to be an issue including new units .
I chased turn signal issues for days and after all possible issues as others have noted above and 3 different
Flasher units finally all worked correctly.

[speedo]

So I tested the relay and it works. In fact I had another relay in the box marked "bad" and it actually tested ok. Now I need to test my plug for power to my relay and also look under the dash for any wiring shenanigans to the plugs or ignition or emergency flasher. I guess if I have power to the relay and no turns, then my problem might be the turn signal switch itself? I have a couple extra switches I could try. I don't have any "electrical contact cleaner" in the shop...and I am pretty sure that WD 40 is not a direct substitute. Might make sense to remove the clamshell and just see how dirty the contacts are inside the switch.

Removing the rug...hmm. There is not just one crack underneath...but a family of cracks. Apparently cracks breed. I'll snap a couple pics and let you guys decide.
Certainly not for the faint of heart. Maybe some black duct tape over the cracks...although that might be a bit too red-neck. Black caulk might be a better fix.

[speedo]

So the early part of the day was testing the headlights and continuity on the corners. Got high beams low beams and running lights...but no turn signals. Decided as my turn signal wand looks as though it had been "chewed on" to replace it. Carefully marked where the replacement wires go and swapped out the turn housing. And voila! Now I have no high-low beams, but when I am on high beams I use the turns...they work although not flashing...hmmm. And when on low beams and I signal a left turn, I get headlights I love chasing electrical gremlins...

[csbush]

I am dealing with some of the same issues. Did you have the whole harness out? It is fairly easy to mix up which plug and receptical go where on the five that go through the firewall by the flasher relay. I had one swapped that affected my instrument lights and license lights. I expected that having them swapped would have been more dramatic with smoke and fire, but it just presented weird test results as I ran wires.

I still have a similar issue to yours in that my lights work but my emergency flasher and blinkers don’t flash when turned on, but I have not checked the relay yet. Waiting to see what you figure out

[wprater]

is this 4 prong really meant to replace the can 901.615.341.10? I’m sorting through hazard issues now as well on my 66.