Dodgy ignition switch

It looks like I’ve got a dodgy ignition switch because occasionally when I turn bike on it springs to life for a second then goes off, requiring me to turn it off and on again. The reason I think it’s a dodgy switch is that a couple of times when I’ve done that it’s sprung to life for a fraction of a second as I’ve turned it off.

Now, in an ideal world, I would get the switch apart to check and clean the contacts but ignition switches seem to be designed not to come apart nicely (presumably for security reasons). So, for peace of mind, the second option would be to replace the switch, but at £180 quid it’s not something that I want to rush into, especially as that would need extra £££ to get dealer to reprogram the immobiliser for the new key, or me having to cut’n’shut the new and old keys.

So, as a first step I’ve put together some bit’n’bobs to help me diagnose the problem and to get me home should it fail badly when I’m on the road.

Looking at bike wiring diagram (now in that kit!) only 2 of the 8 fuses in the fuse box come from the switch, the other 6 go straight to the battery. So the emergency get-me-home solution is two fuses with a wire bridging them, so I can replace one each in the switched and unswitched circuits and get power direct.

Plan B if I’m on an overnight trip, is to wire a toggle switch into that circuit so I can have a handy way of disconnecting power. Switch is missing from photo but I have wires, connectors and loom tape for such a bodge.

A more semi-permanent solution would be to use a relay to switch power, and have that driven by the other contact on the ignition switch which powers the lights, assuming that’s OK. I do have a handy wire under tank from that circuit which I added a couple of weeks ago when wiring up satnav mount :slight_smile:


It’s not unheard of for several different Triumph’s to have issues with the wiring around the headstock getting internal damage, sometimes too tightly routed for lock to lock travel. Next time it plays up try moving the bars, could be developing a break in wiring.

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My ignition switch is mounted down by the engine so not normally flexed in everyday use. But thanks for the suggestion, as part of my diagnostics I can give the wires a wiggle.

Ah, right. :+1: Couldn’t remember your bike, so likely to be irrelevant. :slightly_smiling_face:

My trophy developed an issue where the key wouldn’t always turn the ignition on, so a switch off/on was sometimes required. Plus it stalled once and I think it was those symptoms as the dash went off and required the key to be turned off/on.
It doesn’t sound the same as yours but I found the following.
It didn’t happen with my spare key that I almost never used.
I sprayed halfords electrical contact cleaner into the internals of the switch and left it for a day. It hasn’t done it for a long time now (ha, that’s done it) as I do use the old key occasionally when moving/starting it rather than for journeys.
Just thought I’d mention it in case it helps.

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Thanks :slight_smile:

Be very careful trying to bypass the ignition switch. They may use a different voltage on first startup to stop people hot wiring them. My Hayabusa uses a separate 5v to the ECU when you first turn the key.

Thanks for the warning. I have the wiring diagram and ignition switch comes direct from battery (via the main fuse).

Hi, i have a Street twin 2018,owned it a year now but while scrutinizing things i noticed the when on full left lock the headlight bracket was rubbing the wiring thats around the head-stock area.I have added a layer of thick gorilla tape over the area that is being rubbed so as not to wear through to the wire.Not a perfect solution but i cannot see a way round the issue as yet.It was barely showing signs of wear but belt and braces fix.Ride safe.OApete.UK

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Thanks for the suggestion. I only recently discovered there’s such a thing as ‘loom tape’ and I intend to reinforce some of the split outer sheathing on my front indicators as I found Gorilla tape is too thick and doesn’t stay stuck on. Will have a look at other wiring from front too, though as my ignition switch isn’t on the handlebars I don’t expect that’s the cause of my current problems.

I use self amalgamating tape on my wiring exploits

It’s been a known issue on Street Twins for years. There was a recall for it a couple of years ago, but it was just a bodge, although it still seems to be working OK on mine. It’s a scandal that Triumph didn’t fix it properly years ago with a lengthened or re-routed loom.

So, to report on the conclusion to my ignition switch problems. I tried repeatedly squiring contact cleaner into the switch and tuning it on and off, and in four months of riding since haven’t had a reoccurrence of the problem. :slight_smile:

I am now careful when washing bike to not spay water at the ignition switch.

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