headlight not working after battery change.

[NiK]

I'd want a second opinion also.
When my current Mk3 was three months old, it left me stranded for two months. No juice, nothing at all, despite the battery being in perfect shape.
After one week of head scratching, the dealer resorted to replace the ECU (under warranty of course), and this achieved... nothing!
Six weeks later, Triumph reverted to my dealer with a solution (something Microsoft-stoopid, like rebooting every electronic on-board system).

Frying an ECU with a short on battery leads seems (highly) doubtful to me...

[ijinak]

I'd try Fleabay for a used ECU-that's what I ended up doing on my old Trophy 900 when the ECU fried.

[CaptainTrips]

Originally Posted by ijinak

I'd try Fleabay for a used ECU-that's what I ended up doing on my old Trophy 900 when the ECU fried.

I think, these days, that would be a lot more complicated. You'd need the keys that go with it, the dealer to program it, etc. etc.

[NiK]

Originally Posted by CaptainTrips

I think, these days, that would be a lot more complicated. You'd need the keys that go with it, the dealer to program it, etc. etc.

Confirmed.
When he did it on my Mk3, my dealer described to me all the hassle and pain of swapping the ECU ;-)

[Hawk281]

New update, they replaced the ECU, no change of problem. They swapped out the left hand switch, no change. They are running off of information that Triumph is giving them, which is not solving the problem. The new battery is physically smaller, but the same amperage. That’s where the problem started. Also when they put the new ECU in, they suddenly got error codes,which was no there before. I believe they said low voltage to the headlight.

[CaptainTrips]

Originally Posted by Hawk281

New update, they replaced the ECU, no change of problem. They swapped out the left hand switch, no change. They are running off of information that Triumph is giving them, which is not solving the problem. The new battery is physically smaller, but the same amperage. That’s where the problem started. Also when they put the new ECU in, they suddenly got error codes,which was no there before. I believe they said low voltage to the headlight.

I hope that you aren't paying for all this. Can I assume that they tried an OEM battery?

[Hawk281]

I don’t know if they have. I been thinking about it myself, seems obvious to try that. Going to suggest it today.

[Hawk281]

Ok, an update. After waiting a (what felt like a very long time) the ECU arrived and they installed it and started to program it. Now it showed a couple of error messages, but they weren't concerned, waiting for the process to end. The end result, lights still don't work. Old ECU back in and reprogram. Another call to Triumph, who now suggests ordering a headlight and replace the old one, as there does not seem to be a test for the LED lights to determine if they are shorted out. I was already losing my hair, but this does not help. It won't be here till the first of November, so more time down. Luckily, I have my dirt bikes to ride, but any long trip is out for this year.

[CaptainTrips]

A friend bought a new Chevy Monte Carlo SS in 1983. Halfway between somewhere and nowhere, the engine quit running. He got towed to a highway garage where the mechanic diagnosed failure of one of three electronic modules. No testing available. They guessed and ordered one module, and then another, and then the third. One day turnaround on each try. Got it on the third try. Spent three days halfway between somewhere and nowhere.

I thought we were past all that. My heart goes out to you. Sucks big-time. NiK knows all about that feeling.

[T800XC]

The dealer could have saved a lot of time (and hassle for you) if they'd just tested the CAN-bus for the presence of the headlight signals before dicking around with swapping the ECU.

It only takes a minute to do this but sadly dealers are never interested in such diagnostic methods because they're not listed in the service material.

If the replacement headlight solves your problem I'd love to get hold of the old one so I could fix it and put it on a Tiger 800.