Modern Vespa

Hi,
Not sure if anyone can help me with this. I have a new 2022 GTS 300 Supertech. Have been doing some cosmetic mods such as fitting SIP LED indicators front and rear and replacing chrome trims with black, however, now my scoot is not starting. The front headlight is not coming on when turning key to on, the back brakelight is not working when pressing the levers and the scoot is not turning over at all. These are the things I have checked so far:

Indicators - working
Running lights - working
Horn - working
Seat latch - working
Fuses - Visual inspection of fuses in glovebox - all appear ok
Brown key - scoot will not start. Doesn't make a difference.

The only other things I've noticed is that there is ASR warning light on dash. Don't know whether that is normal.

Does anyone know of any component that would cause both the headlight and rear brakelight not to function? A fuse or a relay?

I am at the point of getting a multimeter and trying to do checks with that but really don't want to have to get it hauled away to a dealership. As the bike is brand new I have ruled out the brake light switches as being faulty.

Thanks for any advice you can offer

Can you hear the fuel pump running when you switch the scooter on?
I don't think the headlight comes on until the scooter is running.

Kill switch?
Side stand folded out?

I hate to admit it but this has caught me a few times.

Not only you…

Thanks everyone for your replies. I can confirm that it is definitely not the kill switch or side stand. Has caught me out before too when I had a GTS a few years ago. I have also tried pressing the brakes extra hard to see if I can get the central LED brake light cluster to work but it's not happening

Fuel pump does prime. I can hear it

Did you replace the brake light with LEDs as part of your mods?

No, so brake light has been left as standard apart from swapping the chrome trim for black trim. I've checked that the connector is fully engaged and the outer leds running lights light up just fine

When you get a multimeter, I'd check the fuses, brake switches, and brake light connection again.

Thankyou, that's on my agenda for this weekend

...as well as the battery voltage, just for kicks.

Will do. I think it's ok as I've got it on a trickle charger and the dash indicates it's over 12 volts but will double check it. Thankyou

The brake lights have to be working before you'll get it to turn over, let alone start. So chase the cause of that first and foremost!

A visual inspection of fuses is next to useless. Get a multimeter and check them properly.

Then check the other fuses, not just the ones in the glovebox.

it should come on as low beam but the high beam switch won't work until the engine is started.

When did that change then? Every GTS I've seen apart from early 250s won't energise the headlight relay until the engine is running and happy.

I'd take a guess and say when they went led (ie hpe)

That makes sense! Thanks for the heads-up. The new circuit diagrams are NOT easy to interpret!

they're also wrong. the A and B link from the top right of the diagram down to the bottom left is crossed over

Managed to find and fix the cause of the brake light issue. Bent pin in the rear light connection. Once straightened out and reconnected brake light is working fine. Bike still not starting though so investigation continuing.

Having fixed the rear brake light issue, bike is still not starting, however I am not getting low beam light on headlight when turning ignition to on so I guess that will be the next focus.

I assume that the bike was running fine before you started modifying it, right? What's the last thing you did before the bike wouldn't start?

It was indeed. Last thing I did before the starting problem was put everything back together, side panels, floorboard, glovebox and then removed the headlight section to replace the headlight trim and put it back. On the dash I am getting a flashing ASR light and then orange engine light. I need to check whether this is normal and expected before starting up

Turning on my Supertech gives flashing abs, asr and solid engine and oil.

Also I was wrong about low beam, it ain't on.

Actually just checked and my memory was wrong, the low beam is not on .(now I gotta work out why I thought otherwise. Hmmmm)

The low power parking/position light comes on.

Thanks for the additional information about the front light. Saved me spending time on that. Finally found the remaining issue. The connector to the starter button had popped loose but was hidden by the dust cover. Now all good again and starting fine. Thanks so much for all the help and suggestions

Thanks so much for the update. It irritates me when the OP doesn't post the resolution. It's like tearing the last page out of a mystery book.

Nicely done.
Will help others in the future.
Thanks