Triumphrat

boondoggle · 08-09-2009, 02:09 AM

My 72 TR6C has gone dead on me.

I was riding around the other day and noticed my headlight was out so I tapped on it and it flickered but never came back on fully. When I got home I pulled the old one out and went to check the brake light while I was was it.

The rear taillight wasn't coming on but the brake light worked - once, then it stopped. So I figured maybe it was blown out too. But was suspicious so I pulled out the little assembly. I noticed the red 'ground wire (?)' from the tail light assembly (the pull out piece) to the ground was coming off a bit. So I soldered it back on. but nothing changed.

A few days later I replaced the bulbs but they still didn't work. Tried to start the bike, and now it won't even start. Tried the horn and it didn't work, the turn signals don't work, nothing works.

Checked the fuse on the negative battery cable it was blown (it was a 20A). Replaced it with a 30A - manual calls for a 35A but I could only find a 30A.

Still nothing.

Kept checking wires, found one of the blue wires from the crankcase to the ignition area was broken. Replaced the bullet connector. Still no luck.

Checked all the connections on the ignition switch, but still nothing. The red oil pressure light doesn't even come on. Bike doesn't even sputter.

The battery is fully charged.

I'm kind of stumped right now. Can't think why I would be able to drive all the way home and have an electrical gremlin show up because I was replacing the bulbs. It's not like I can 'blow out the ECU' or anything.

I looked in the manual but it only references the ignition for troubleshooting.

This is driving me crazy.

What would you check next?

Thanks,
sb

epynt1050 · 08-09-2009, 05:21 AM

Do not have wiring diagram for a 72 model to hand but all models are similar. Feed from battery (positive earth) goes to the main (ignition) switch. From the main switch, power is then split to lights, coils etc.
Check that the fuse has not gone again - if so suspect short somewhere.
If fuse OK, check the feed to the ignition switch for 12v with ignition off. If you have 12v going to the switch, turn ignition on and check for 12v out.
If you do the above and are still having problems, get back and let us know results and the people here will be glad to help further.

Caulky · 08-09-2009, 06:40 AM

According to the wiring diagram, you should have a 4 position ignition switch.
(mine is only 2 way...ignition on or off, with switches on the handle-bars for various functions)
You replaced the fuse, is it still OK?
If it is good, it rules out the zener, rectifier and alternator wiring.
If you have the 4 way ignition switch, turn it anti-clockwise (only lights)
and re-check the fuse.
The speedo and tacho lights should be on.
If not your ignition switch is faulty.
If you`ve got this far with no trouble, check the brake lights.
Then each light in turn.
This will eliminate the lighting stuff.
The fault is in the ignition circuit. Switch the ignition switch one step clockwise (ignition only).
Oil pressure light is on, horn should work.

GrandPaulZ · 08-09-2009, 12:59 PM

Sounds like the keyswitch to me.

Hot-wire it to verify.

If it was failing by looseness or bad contacts, that can certainly cause bulbs to blow and other maladies.

boondoggle · 08-12-2009, 03:01 AM

Apologies for the late reply. Got hung up on some other things.

Seemed like a possible ignition/key switch to me too. None of the 4 positions has any response though and that seems like a pretty massive failure for a sinle component. But who knows.

That hotwire idea is interesting. Which wires do I cross? Guess I could always check for continuity on the switch but I'm not sure which contacts to test for an open circuit. Will have to see if that info is in the manual.

Had to repair a poor connection on the switch once before. Checked that and it seems fine though.

Will try to get some garage time in tomorrow for some troubleshooting.

Thanks for the input,

sb

Caulky · 08-12-2009, 06:36 AM

Pin 1 has the brown/blue wires from the fuse, zener and rectifier.
So with the fuse fitted, it`s at -12V wrt chassis/earth.
Pin 2 has white wires going to ignition components.
Pin 3 is the lights. (Brown/green?]
*Remove the fuse*.
In the OFF position, pins 2 & 3 are connected to each other.
Remove the wires from the switch. 2 & 3 short, 1 is open circuit wrt 2 & 3.
------------------------------------------------------------------
Turning the switch anti-clockwise (lights) connects pins 1 & 3 together [short].
Pin 2 is open circuit.
------------------------------------------------------------------
One click clockwise is ignition only, pins 1 & 2 short, 3 open.
------------------------------------------------------------------
Two clicks clockwise is ignition AND lights. Pins 1, 2 & 3 all short circuit.
Any other combination or intermittant readings means the switch is faulty.
If you have an open circuit, which should be short, you could spray some switch cleaner in it.
Or maybe its a sealed unit.

boondoggle · 08-17-2009, 02:58 AM

Well, it works again. And I'm absolutely certain The reason why escapes me.

I made sure all the grounds and connections from the battery were good. Reseated the Zener diode connection and reseated the connections on the switch. Turned the key and voilà!

Strange switch though. I've actually got four connections on mine. There's a blue/yellow wire that isn't mentioned in the manual. My switch doesn't have the proper operation per the manual either. Counter clockwise doesn't turn on parking lights etc.

Not a very descriptive portion on the switch n the manual. My switch has a bunch of pins on it. Not sure if some are 'spares', dead or what.

Ah well. At least it's working again. Now I know what it feels like to get a visit from the prince of darkness. At least it happened in the garage eh?

Cheers,
sb

Caulky · 08-17-2009, 05:41 AM

Well done boondoggle.
I seem to remember, twin coloured wires with blue are lighting that are routed via the handle-bar switches.
But mine is a different model to yours.
Multiple pins are probably common, e.g. pin X has 3 tags...so that you dont get one tag with ten wires on it.
You could wire the switch as per the wiring diagram, if you`re inclined.