TR6 Test 75 TR6 Hazard Switch?

[Jim Shangle]

I am a new TR6 owner (CF36623U) and am going through my new project fixing and upgrading things that are in need. My hazard and turn signals are not working. In reviewing the wiring diagram it looks like the turn signal switch (TS) is dependent on the hazard switch (HS) being good.


Is it possible for the HS to be good and the TS being bad thus neither circuit working?


How can I test the TS and HS to see if either is bad before I go out and spend the money replacing them.


Thanks for your help.
Jim

 

[NutmegCT]

Jim - welcome to BCF.

Have you checked the wiring diagram available here:

https://www.advanceautowire.com/tr2506.pdf

https://www.advanceautowire.com/latetr6.pdf

Tom

 

[TR3driver]

No, a bad turn signal switch wouldn't keep the hazards from working. But don't forget, it might be more than one problem. Occam's razor doesn't always work, particularly when it comes to electrical systems on British cars.

One test to prove that the TS, wiring and bulbs are all good would be to remove the TS flasher and supply 12v directly to the load side of the socket. Then when you operate the turn switch to the left, the left turn lamps should light solid; ditto for the right. (If you don't know which is the load side, just try one and then the other. It won't hurt to power the other side, though you may see the gauges move as though the key were on.)

If that looks OK, make up a short bare jumper with two quick connect tabs and use that to replace the TS flasher. Turn on the key and TS switch (either left or right), and check from the jumper to ground for power. If no power, you've got a bad connection farther up the line, or the hazard switch is bad. The reason for making the test this way is because a bad connection can sometimes pass enough power to light a test lamp (or read 12v on a meter), but not pass enough power to actually light the bulbs. So testing without the circuit complete can have you chasing your tail.

Obviously, if supplying external power works, and there is power getting to the flasher, then the flasher itself is bad (or is not making good contact in the socket).

 

[arcom]

FWIW, my hazard lights have never worked but my turn signals work fine. I can hear the hazard switch clicking but the lights don't flash.

 

[Jim Shangle]

Thanks Randall. So I had already ordered a new Hazard switch so I installed it. Still no flashers or turn signals. I then did the 12v direct to the load side of the TS flashed circuit (under the passenger dash) and got nothing. So I have a wiring problem, and now an expensive spare hazard switch. Any more suggestions on where the problem may be?

Jim

 

[Jim Shangle]

A little more info. I applied the 12v jumper to the load side of the hazard flasher (near the fuse box) and the flashers worked but the turn signals still didn't. Now I'm really confused.

 

[TR3driver]

Since I'm not sure where the components are located on a '75, I would probably check at the rear turn bulb holders next. They're fairly easy to get to. Leave the hot wire in place and the turn switch on, see if power is getting to the bulb holders. When I got my first Stag (which uses the same bulb holders), none of them worked! There is an article at https://www.buckeyetriumphs.org/technical/Electrical/TR6Sockets/TR6Sockets.htm that shows the problem and a way to fix it. (However, mine were so bad that I had to use a piece of wire to bridge the gap.)

The replacements I got from TRF & Rimmers were an improved design, that uses a separate tab for ground. So to fit them, I had to make up some ground wires. One possibility might be that someone has replaced your holders and not added the ground.

Obviously, if there is power and ground at the bulb holder, then either the bulb or the holder is bad. Strange that all 4 are bad, but not impossible. However, it's more likely you'll find no power, and that leaves the turn switch and the wiring to/from it. So my next step in that case would be to take the switch loose enough to probe the connections at the switch, and see where the problem lies. I don't know exactly how similar the TR6 switch is to the Stag switch, but the Stag switches are very fragile (in my opinion) and cheaply made (although you certainly couldn't tell by the cost to replace them!). So be careful not to break anything.

PS, Oops, I didn't see your last post when I wrote the above; and now I've got to run. But you have confirmed that the bulbs & holders work, so you can skip directly to the part about testing at the turn switch.

 

[TRopic6]

A little more info. I applied the 12v jumper to the load side of the hazard flasher (near the fuse box) and the flashers worked but the turn signals still didn't. Now I'm really confused.

Aloha Jim - I've got CF36711U, so our 6s are from the same litter! That's good that all the lights work - maybe the trouble is your hazard switch isn't switching power to the turn signal side. When it's pushed in, the green wire (12V) is connected to the light green/green striped wire. The switch is hard to get to, but there is a plug-in connector block that hangs down from the switch. Try unplugging it and using the Advance Auto Wire diagram, test for voltage. You can also jumper the appropriate wires to simulate switch action to power the turn signal switch.

Jeff
74.5 & 75 TR6

 

[Jim Shangle]

I'm back with an update. As I said before I replaced the hazard switch and hazard flasher and that got the hazards flashing but still I had no turn signals. Now I have replaced the turn signal switch and the turn signal flasher. Behold, I have the left turn signal blinking but no right signal. OMG, this is torture. Looking at the wiring diagram leads me to believe I have a wiring problem (broken wire or short) between the turn signal switch and the junction where the wire from the hazard flasher joins on its way to the lamps.
Anyone think differently? This is a great forum and I really appreciate all the advice. It amazes me how much I don't know but I'm not afraid to jump in and learn for you all.

Aloha Jeff. I have a question for you. Your TR6 was built shortly after mine and they are 1975 model year cars. My question is 'does your car have the EGR light on the dash and the EGR counter near the fuse box?' The 1976 wiring diagram shows the EGR light and counter but the 1975 wiring diagram doesn't. Was this a late 75 addition? Just curious.

thanks all,
Jim

 

[Gliderman8]

Just a thought..... the bulb holders on the TR6 are notorious for not conducting the ground wire as the internal tab stops making contact with the base. Some people try and bridge the gap with solder with some success,
Why not switch the known GOOD left bulb holder to the right side and see if it works before anything else.

 

[TRopic6]

Jim,

Congratulations on the R&R for all those electrical bits - should be all new. Pushing the hazard switch in connects 12v to the turn signal switch via the flasher. The TS switch simply sends 12v to one side or the other. If the lefts blink OK, then try Glidermans idea and swap bulb holders. If you have a voltmeter or test light, see if 12v is getting to the right side wire. Are the turn signal switch to harness connections good?

Yew, mine has the EGR counter & light. I think that was federally mandated to start Jan of 1975, creating the infamous '74.5 series. The first half of what would otherwise have been '75 cars were able to use the '74 drivetrain (without air pump, EGR, etc) so were a little bit different.

Jeff

 

[Jim Shangle]

Finally got it figured out. Turns out that the NEW turn signal switch worked going left but not right. I returned it to Moss and am awaiting the replacement. Used a jumper wire to finally find the problem. Now on to the next projects, touch up a couple paint chips and full body polish and wax.
Winter projects also include packing wheel bearings, improving the grounding of all lights and and replacing the transmission and diff fluid.
Thanks all for the advice. I certainly learned a lot about Triumph electrics.
jim
75 1/2 TR6

 

[poolboy]

Has anyone recommended this book ?
It'll save you time and trouble.
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=82132