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Tips
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Turn signal wiring

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Cain

Cain

Jedi Trainee
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I'm troubleshooting my turn signal lights - at this point the lights neither come on nor blink. All the connections are made at the lights, turn signal relay, and hazard switch.

It was pointed out to me that the hazard switch must work for the turn signals to work - is that correct? If so, must the hazard relay also work for the turn signals to work?

Could someone lay out the routing of the turn signal wiring to me? It seems that the wiring goes from the turn signal switch to the turn signal relay back to the hazard switch or something like that.

If the turn signal relay has failed, will the lights still come on but not blink?

What about the bulbs? If I have one bad bulb or bad bulb connection in one of the four signal lights, will none of the four lights work?

Thanks
 
Hello Cain,
I have a Triumph sedan, not a TR6 but I'm guessing that the wiring is very similar.
From what I'm looking at the turn signals should work whether the hazards function or not.

With the ignition on, you should have 12 volts at the turn switch, light green\brown wire. If not you need to go back to the turn signal flasher relay, the green wire is the feed which comes from an ignition fed fuse. If you have power at the flasher relay, (green wire) but not at the light green\brown the relay is U\S. If you do have power at the turn switch, you should, with all odds have at least one light working if you select right or left turn. If one or more lamps are bad or have a bad ground at the lampholder the opposite end lamp should stay on.

Let me know how you get on.

Alec
thirsty.gif
 
Cain,
I just went through the same problem, or at least a similar one. The left turn signal on my TR6 stopped working. Alas, as this had happened before, I went right to the source: the darn ground spring in the socket wasn't grounding anymore. Took it apart and soldered the finger spring to the area it was supposed to ground to. Works perfect. Check out this same problem on the Buckeye Triumph website, soldering light sockets.

Bill
 
For the '70-'71 TR6's, the hazard switch has to work for the turn signals (TS) to function. The TS switch is fed from the TS flasher across terminals 3 & 4 of the hazard switch. Suggest you (1) cycle the hazard switch a few times to remove oxidation at those terminals and (2) verify 12V at the light green/brown tracer wire connector coming from terminal 3. If you have power there, you should at a minimum be able to get your rear lamps to come on (assuming, of course, your TS switch contacts are good) since ther rears don't receive power from the hazard relay. The fronts are powered indirectly from contacts C1 and C4 of the hazard relay via duplex connectors going to the rears.

Enough of that for now. Check it out and we can go from there.

Rick O.
 
OK, I finally got a chance to look at everything.

First I determined that I had juice going into and out of the turn signal relay.

Then I tried what Rick O. suggested and flipped the hazard switch several times. After a couple of flips, I heard a couple of crackles and pops and noticed a beautiful on/off clicking sound coming from the hazard relay. So, at that point my hazard lights/system was working which is something that hasn't worked since I've owned the car.

However, I couldn't get any juice going into the TS switch so I unplugged those two wires from the hazard switch and jumpered them together. That gave me power to the TS switch. I then checked out the TS switch and it is viable - both right and left TS lights came on when I had the TS switch in the respective position.

But, the TS lights weren't flashing - they just stayed on.

Questions:

1. Is it safe to assume that the TS relay doesn't work? (Juice goes through, but no on/off clicking. Checked the resistance and it is constant.)

2. Would it be okay (safe) to leave the two TS wires from the hazard switch jumpered (i.e., bypass the hazard switch)?

Thanks for your input.
 
That's great! Did you hear any clicking sound form the hazard flasher attached to the left wing? I assume that once you got the hazards going, you observed that all four TS lamps were flashing. That eliminates the possiblity of burned out lamps as being the source of no left or right TS flashing.

I would investigate (replace) your TS flasher (NOTE: there is no TS relay, just a flasher) located above the passenger footwell. If that doesn't help, you will need to check the tail lamp sockets for corrosion.

I see nothing wrong with leaving the hazard switch jumpered, but you'll lose the hazard function. The hazard switches are quite rare and difficult to find at a reasonable cost.

Rick O.
 
I exaggerated a little earlier to save some typing time - not all lights were flashing when the hazards were on - just the two with good bulbs in them. So, the validity of all flasher lights had not been inspected yet.

I got the new flasher unit and new bulbs installed on the two lights that weren't coming on. After doing so, the driver's side lights flash correctly, but the passenger's side just stay on and don't flash.

I started playing around with the lights to test the running light feature in the new front bulb and it was blowing the fuse to the running lights. I traced the problem to a bad ground on the passenger front flasher - one of the lights with a new bulb which wasn't tested previously because it had a bad bulb.

I also assume that once this ground is fixed, my passenger side flashers will work properly. Correct?

Question: Must I contact a new ground back into the black wire in the wiring harness, or can I just attach a new ground from the flasher light to the car body?

Thanks
 
Cain--Yes, bad/nonexistant grounds are the source of many problems, so you should achieve success. The tail lamp sockets are notoriuous troublemakers and you might consider R&R'ing them per the Buckeye Triumphs instructions. As far as reconnecting the loom ground wire, I would advise you do so. There may be other devices relying upon it.

Hope everything works out for you.

Rick O.
 
I rest my case.
Oh, and yes, you can solder a ground wire to the socket and run it directly to the body. I just afix it to one of the selfthreading screw holding the trunk panels in.

Bill
 
Thanks for your responses fellas.

I failed to mention this in one of my previous posts, but I soldered the ground spring in all of my rear bulb sockets using the "Buckeye Triumphs method" some time ago. However, I never did anything to my front sockets and that's where the problem is. But, sometime this weekend I may do exactly as Dr. Bill suggested and solder a ground wire directly to the socket and affix the other end of the wire to a nearby screw.

I'll let you know how things go and hopefully bring this issue to closure.

Thanks
 
OK. So it didn't work as I planned and I'm at a loss. Help!!

I now have solid grounds on all four signal lights, but (as before) my driver-side signals blink, and my passenger-side signals come on but don't blink.

Please note that the only wiring done differently is that I bypassed the hazard switch. I wouldn't think this is a problem because according to the wiring diagram in the Bentley manual, both the driver and passenger-side TS wiring are wired identically. (i.e., If bypassing the switch works with one side, it should work with the other as well.)

Any more suggestions?
 
Hello Cain,
double check the bulbs on the passenger side, especially if it is a double filament. The high wattage filament is the flash and if you have a tail or side connected that could be the problem.
The flasher relay is OK as it works on one side, but the other side is not drawing enough current to cause the relay to flash.

Alec
thirsty.gif
 
Piman, what exactly do you mean by a 'tail or side connected'?

I have switched the front flasher bulbs with each other, but this hasn't fixed the problem.
 
I was having problems with my lights and the hood was not properly grounded, the ground wire was connected to the fill plug on the steering and I changed it to the frame and now they work. For what it is worth and old Triumph Mech. said not to ground to anything that had a rubber seal or grommet or a fill plug. It was neat, he hooked a pair of jumper cables to the neg post on battery and the other leads to the hood, magic the lights worked who else would have known to do that
 
Wouldn't you know, last night I developed the same problem in my GT6. Left side TS work, right side ones just stay on--no blink.

I'll check the sockets and grounds as indicated above.

Any other ideas on how to fix it?
 
I got it fixed. I had two problems - the bulb socket wiring and the thermal flasher. The wires in the right front flasher bulb socket were backwards, so the running light was brighter than the flasher. Also, with the help of a kind gentleman's suggestion, I replaced the thermal flasher unit with a solid state (electrical) flasher unit. I got it at AutoZone for like $7. Everything works now.
 
Hey Cain, thanks for the info. What's the part number and manufacturer of your solid state flasher unit?

I'm wondering if it will fit a GT6. Does anyone know?
 
I just got a generic/universal one at AutoZone. It's a Tridon EL12-C.

They have multiple ones to choose from depending on how many wires you got going in/out. The only drawback is the one with two prongs (that is needed for the TR6) is round and the housing mounted to the footwell for the stock thermal flasher is square. (i.e., I don't know if the round solid state flasher will fit in the square housing - I haven't tried.) So right now it's just hanging under my glove box - er where my glove box is supposed to be installed. But, it's nothing a little contact adhesive can't take care of.

OK - so I'm not a Triumph purist.
 
To answer your second question, I just checked the Autozone website and it says the flasher for a '68 (MKI) or '69 (MKII) GT6 is a Beck/Arnley 202-0014 for $12.35.
 
Thanks for the info, Cain and everyone.

Also, thanks for the heads-up on the AutoZone website. It's very useful.
 
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