TheSamba.com :: View topic

Sun Jul 16, 2017 2:46 pm

My brother and I rewired my 73 Thing’s instrument harness. Once everything was in we determined I needed a new turn signal switch. Now that everything is installed this is my issue…turn signals don’t work. Emergency Flashers do work. When I click on my high beams the high beams go on but so does my horn. I remember ready about this a while back and can’t find the answer now. Help Please.

Sun Jul 16, 2017 7:22 pm

You will need to re-visit your work, taking it one circuit at a time.

Check this wiring diagram:
https://www.thesamba.com/vw/archives/info/wiring/181_Wiring_Diagram_4-73.pdf
Be patient, double check your work, and you will figure it out.

Tue Jul 18, 2017 5:07 am

Yeah I have that diagram

Tue Jul 18, 2017 1:16 pm

Let's talk about the turn signals first. I know you have the diagram, so let's use it to do a little deduction. You said that the emergency flashers work. That will help narrow it down.

The power gets to the emergency flasher switch via two means. There's unswitched power coming from fuse 10 through a red/black wire to terminal 30 on the switch. Switched power comes from fuse 1 via a green wire to terminal 15 on the switch. The emergency lighting is powered by the red/black unswitched wire, and the turn signals are powered by the switched green wire. The emergency flashers work, but the turn signals don't.

So, with the key switched on, see if there's power at the green wire at terminal 15 on the emergency flasher switch. If there isn't, make sure the other end of the green wire is properly connected at the downstream side of fuse 1.

If there is power to terminal 15 on the emergency flasher switch, let's move on. Whether switched or unswitched (depending on the position of the switch), power leaves the emergency flasher switch at the + terminal via a white wire and goes to the flasher relay. Intermittent power leaves the flasher relay via the blue wire and ends up back at the emergency flasher switch at terminal 49a. Since the emergency flashers work, we know that those two wires are correct and doing their thing.

Once the power gets to terminal 49a on the emergency flasher switch, one of two things happens. If the emergency flasher switch is on, the power runs through the switch to terminals L and R on the switch, where it is distributed through the turn signal lamps at each corner of the car and finally to ground. Once the power finds ground, the flasher relay does its thing and the lamps blink. Again, as your emergency flashers are working, we know all that is good.

OR, if the emergency flasher switch is off, the power is allowed to jumper away via the black/green/white wire at terminal 49a on the emergency flasher switch to the turn signal switch. From there it is distributed (depending on the position of the turn signal switch) to either the black/green wire or the black/white wire which lead — yes — back to the emergency flasher switch, to the L and R terminals of the emergency flasher switch where, without going through the emergency flasher switch, the intermittent flashing power goes off to the left or right side turn signal lamps and finally to ground. Whew.

Because the emergency flashers work, we know the following.
The wiring from the emergency flasher switch to the turn signal lamps is good.
The bulbs are good.
The grounds at the lamps are good.
The unswitched power from fuse 10 to the emergency flasher switch is good.
The wiring from the emergency switch to the flasher relay and back is good.

What we don't know:
Is there power coming from fuse 1 via a green wire to terminal 15 on the emergency flasher switch? As I said above, with the key on, check for power at terminal 15 with a meter. My bet is that is the problem. Check the connection of the green wire at both ends.

If that's not the problem, check that the connecter at the turn signal switch is firmly plugged in.

Let us know what happens.

ETA: if someone offers you a free wiring diagram, even if you already have it you should say thank you.

Thu Aug 31, 2017 10:51 am

Thanks Captain. I'll be opening it back up this weekend. Hopefully we'll get it this time

Sun Sep 03, 2017 2:40 pm

The outcome... I now have everything working properly. The new wiring harness was missing the S- wire for the horn was missing and the power wire 49A was in P1. Thanks for your help. My brother has now moved onto my wiper motor. I love it when he visits!