(more) Turn Signal Woes - Sanity Check Please

[jlb]

First, I know that turn signal issues are old news around here. I've read every possible thread on the forums, I do have the correct wiring diagram handy for my '74 tii. I do have a digital multimeter, and generally know how to use it . . .  

 

Problem: my turn signal stalk switch does not activate the turn signals.  I had previously had the same issues when I bought the car awhile back, and eventually solved it through the 'shotgun' approach of replacing the flasher relay, signal stalk, and hazard switch. That solved things for about 6 months. Last week, the problem re-emerged.

 

Part 1: Troubleshooting thus far:

 

- Fuse #6 (purple/white): 12v is present across this fuse when the ignition is 'on', as expected.

 

- Hazard switch (#54 in wiring diagram): when the hazard button is pressed, all four turn signals flash intermittently as designed. When this happens, the gauge cluster bulb does flash on and off correctly. So, the flasher relay, turn signal wiring dash bulb, and hazard switch all appear to be functioning correctly overall. I do have a jumper wire installed to bridge 12v power from pin 15 (purple/white) to pin 49 (green/violet), which I installed previously as part of my past troubleshooting. So, pin 49 (green/violet) now has 12v power when the ignition is 'on' as it should.  

 

- Flasher Relay (#55 in diagram): the green and violet wire mentioned above connects to the flasher relay, and does read 12v at the relay terminal as expected. The green and yellow wire (#134) also reads 12v at the flasher relay. So, we have power as expected coming to and from the relay. We also know (from the hazard switch test above) that the relay 'clicks' as designed when the hazards are on. Just in case, i've ordered another relay to have on hand as a spare, coming soon...

 

- Turn Signal Connector (#59 in diagram): In order to test continuity in the signal switch itself, I unplugged it from this connector, and tested the pins at the connector itself. The green/yellow wire referenced above from the relay passes through this connector, and does read 12v power. So, we have power continuity from the hazard switch > relay > connector. HOWEVER: if I connect a jumper from this green/yellow wire to either the blue/red or blue/black terminals adjacent to it (which should activate the turn signals?), nothing happens. No 'click' from the relay, no turn signals. If I am reading the diagram correctly, I should be able to activate the signals with this test as a way of eliminating the turn signal stalk switch from the equation. So, the fact that I cannot activate the turn signals by bridging power at this connector should mean that the signal switch itself is NOT the problem, as described below:

 

- Turn Signal Stalk Switch (#60 in diagram): I have two turn signal stalk switches, since I bought a (used) replacement as part of my previous troubleshooting efforts. One of them is un-touched aside from contact cleaner sprayed inside, and the other has been taken apart completely, cleaned, reassembled. I have tested both for continuity using the DMM, and both pass the continuity test when the switch lever is activated to either left or right, as expected. So, I believe that the signal stalk is not to blame for my current problem.

 

Part 2: What Next / Sanity Check???

 

- Can someone confirm that, on the white turn signal connector (#59 referenced above), I should be able to activate either the left or right turn signals by jumping the green/yellow to the blue/red or blue/black as described in my test above? If so, then what does it mean that my attempts to do so are failing? It appears that both the blue/red and blue/black wires proceed directly to the turn signal bulbs themselves, and we know that those are fine since the hazard switch is able to activate them. 

 

- In order to better understand the hazard switch's role in all this, can someone confirm that the ONLY role that the hazard switch plays in the turn signal operation is to feed power to pin 49? In other words, I could disconnect the hazard switch altogether, but jump between the female pins 15 and 49 and still have turn signal operation? That's my understanding...

 

- I honestly don't know why at this point, but i'm feeling like the flasher relay may be at fault here. Any suggestions on how to test it on its own?

 

- Any other tests to perform? I'm running out of ideas here...

 

 

Thanks in advance, and sorry for yet another turn signal thread!

 

 

 

 

 

 

 

 

[TVeye]

I'll have to re-read this but, I'm in the same place.

I think the Hazard Switch is our problem. My flasher relay was

getting no power. I jumped the GRN/Vi wire and all turn signal lights

lit solid with no flashing with hazard button in. With button out, only the button lit up.

Hazard Switch is my main culprit now.

[AustrianVespaGuy]

Do not despair, I'm sure we'll be able to get both of you guys sorted.

@jlb Your troubleshooting and understanding so far is spot on, but here's the interesting point in your analysis:

On 2/11/2018 at 1:10 PM, jlb said:

HOWEVER: if I connect a jumper from this green/yellow wire to either the blue/red or blue/black terminals adjacent to it (which should activate the turn signals?), nothing happens.

This part doesn't really add up. Since the hazard switch and flasher both work, then yes this should work too.  All the hazard switch does is connect the gn/yl wire to BOTH the bl/bk and bl/rd wires, whereas the stalk switch connects the gr/yl to just one or the other.  So there aren't many possibilities here.  Check continuity along the blue/black/red wires. Perhaps they're well connected to each other (lights and hazard switch) but they are poorly connected to the terminals of the #59 connector.  Also try jumpering to BOTH terminals at once; an old original flasher could be a little finicky and it's possible that it needs to see the load of more than just 2 bulbs before it will function properly.  Again, aside from perhaps the relay, I agree that all of your components seem to be in good working order and suspect wiring not components to be the culprit here. Your other assertions are also correct.  With the car on, (and hazards off), all the hazard switch does is power the flasher unit.  With the car on or off, when you activate the hazards, it just connects the gn/yl wire from the flasher to both sets of bulb wires.

 

@TVeye I think I need a little more information on your issue.  What did you jumper the gn/vi wire TO? Also, do the turn signals also not work, or is it only the hazard switch that is giving you problems? Let me know!

 

[TVeye]

jlb has a problem in the turn signal switch. After cleaning mine, I fixed that.

My problem is no power to flasher relay, I jumped from the constant power in the headlight switch.

[jlb]

Thanks for the input guys!

 

I've made some progress on this since posting. It turns out that my power from the fuse box to the hazard switch pin 15 (the violet / white wire) was somewhat erratic. I had been operating on the assumption that this wire was getting proper voltage based on some early tests, but further continuity and voltage testing leads me to believe that there's not clean continuity back to the fuse. I still haven't resolved it entirely, but I did end up switching my jumper over so that the turn signal power (pin 49) is being fed by a different 12v source (I think it was pin #30). All turn signal system components work perfectly when this connection is made. So, I have my turn signals working fine temporarily, and some confidence that all of the actual components are in good working order. Now I need to troubleshoot that one violet/white wire from the hazard switch back to the fuse... 

[AustrianVespaGuy]

Well fortunately that wire doesn't go very many places! Should just be a single straight run from the hazard switch to fuse #6, with maybe an extra little pigtail for the radio at the end, but that's it!