What Causes Key Switch Failure?

[DEcosse]

... will it help to do the test you suggested several months ago of using needle nosed pliers to bridge fuse 2 and 5 with the key on? ...

No - you are far past that stage of diagnosis now. It WILL come on if you bridge that so will not prove anything we don't already know.

 

[dobro]

Is there a significant possibility that the tune in the bike could have become corrupted resulting in my problems starting the bike?

 

[DEcosse]

No, none

 

[dobro]

So that confirms that it is the main input to the key-switch that is not completing the circuit through the ignition and headlight circuits - the brake & turns are on separate pole through the switch which explains why that works.
And cannot be on the output side of the switch, since multiple poles are being affected; so confirms you are losing power at the input of the switch plate.
That puts the problem at Fuse 2, the key-switch connector wires/terminals (on either male or female) or the input wire at the key-switch contact plate itself.
When you get a 'repeat' failure it is either a high probability failure item (the key-switch on the T I would not consider this to be compared to the Classic/Std) or it is something else that was masked temporarily.
Since you did appear to get some temporary relief, when installing a new key-switch (or maybe just the physical act of disconnecting and reconnecting) it puts the connector set as a high-level suspect - and see the pics of that other one to show how that can be an issue)

Here's a potential for what could be a low-cost easy-execute solution or at worst a valuable aid in the problem diagnostic:

Connect a fused wire from the battery positive directly to the White wire of the Key-Switch, just beyond the key-switch connector on the key-switch side - a PosiTap connection will make this an easy connection that is minimally invasive if you decide it is temporary for testing.
That will bypass Fuse 2, its socket, the White/Blue wire and the terminal on each side of the White/Blue to White connection in the key-switch connector.
If all is then good, it says problem is in that defined 'bypass' region; if it is not resolved, then yes, that would also confirm problem to be in the switch itself.
If that connection does fix it, if you want further diagnostic using this aid, you could then switch the PosiTap to the White/Blue wire on main harness side of the connector set - if it then fails, problem is your connector - if not, puts you back at the Fuse Panel.

If you need me to, I could make that bypass link up for you with a quality Fuse Holder (MetriPack 630) and battery lug and PosiTap

If you want to source yourself see here - Order Online- Discounts and scroll down to item ZRTL-643-6 ; 12-18ga 6-piece, $8.95 shipped
(cheaper to buy directly from PosiTap with free shipping than to buy on-line from vendor or EBay)

 

[dobro]

DEcosse, I would like for you to make the bypass link for me.Please send payment info to me. Thanks.

 

[dobro]

The problem causing my R3T not to even light up has been found and it's just what DEcosse said at the beginning it most likely would be: the infamous white wire on the key switch side of the connectors. The mechanic told me he'd checked that wire (after DEcosse informed me that it was the most likely suspect) and that it was okay. A new key switch and 6 months later the problem repeats and the mechanic again tells me he has re-checked it and it's okay. Yesterday the shop owner hauled my bike in to try the connector bypass that DEcosse recommended. After he left, I pulled out the old key switch that was replaced 7 months ago and, for the first time, used a magnifying glass to inspect it (my near vision is lousy) and I saw clear scorching of the seal on the white wire in the male connector and light browning of that wire. The owner called me a couple of hours later to tell me what he found and I said "go ahead, but I already know the problem". He said a white wire had gotten so hot it melted so he replaced that section and installed new connectors. Apparently, the new connector's white wire/pin (that came with the new key switch) also became damaged from the same loose connection that damaged the first one, or maybe a damaged socket in the female connector, which had not been replaced, ruined the new wire/pin.

Thanks, again, DEcosse!

 

[DEcosse]

Good to get conclusive answer.
The problem of the new switch connector also failing almost certainly points to the prime mover being the female one on the main harness side; so important that one is replaced also.
Hopefully your man has a good crimping tool and the capability to re-terminate the new connector properly!

The good news is you could replace your original switch if you want the original key (but should replace that connector, or at least the one terminal) - and then you'll have spare switch, either way (but hopefully never need it!)

 

[dobro]

Good to get conclusive answer.
The problem of the new switch connector also failing almost certainly points to the prime mover being the female one on the main harness side; so important that one is replaced also.
Hopefully your man has a good crimping tool and the capability to re-terminate the new connector properly!

The good news is you could replace your original switch if you want the original key (but should replace that connector, or at least the one terminal) - and then you'll have spare switch, either way (but hopefully never need it!)

DEcosse, he told me he used connectors that are much heavier duty than those I'd ordered and that he replaced both of them. As far as his crimping skills, at this point, I'm generally skeptical. If it fries again I'll do as you once suggested and go to an auto electrician.

 

[DEcosse]

Pretty bizarre to have not used the oem connectors which are PLENTY big enough for the current application.
Means you have removed any possibility of a plug n play solution if ever needed down the road and now have a non standard main harness - sorry, would not have been my choice ....

 

[Tripps]

FWIW, I had problems with my ignition not working sometimes, ran half a can of electrical contact cleaner through it, washed out tons of crud, been fine for a month and a half now.