I was fitting a cheap eBay tail tidy to my Monster 1200s this afternoon and checked indicators and number plate light were working before tightening up. To make a long story short, here's my problem: 1. New number plate LED now not working when it was working before I tightened everything. 2. Tail light not working, but brake light and headlight are fine. 3. Taking things apart, I saw that two bullet connectors for the number plate light were touching: their plastic sheaths had ridden up. So I thought I'd blown a fuse, but in the manual it says there's only one 5 amp fuse for "Lights", so with the headlight working it must be OK? But when I reconnected the previous number plate light, it wasn't working either. All thoughts much appreciated. Thanks
Was the original number plate light led? Might be something has touched and shorted but in my experience Ducati’s do some weird things when you add leds.
The original was LED, I believe, but the previous owner had fitted a tail tidy made of slowly crumbling aluminum which is why I decided to replace it with a steel one.
OK. I hate electrical problems. They are a mystery to me. Any thoughts about what I check/do next? Ta
AI advised me to check the fuse for the BBS module. No joy. All fine. Swapped it over anyway... problem remains.
Maybe not if the headlight and tail lights are all LED. I had initially thought that it was probably and earthing fault but since the stop light shares the same earth and it's working then that can't be the case, so it must be a supply issue. From looking at the wiring diagram, the power for the tail light, number plate light and the pilot lamp inside the headlight appears to come from the dash OR the ignition switch. The diagram gives no indication of the connections inside the ignition switch. It could be worth turning the ignition to PARK to see if the tail light and number plate light come on. The BBS unit has nothing to do with the tail light circuit but the brake light is driven from it.
The rear light consists of a bigger upper section and a smaller lower section. The upper section comes on when I use the brakes and when I select Park. The lower section does not come on at all. Headlights on, nothing from the tail. In Park, nothing.
If the two bullet connectors shorted, then the wiring may have burnt thru... like a fuse. Because of the LED's, the wiring gauge is pretty thin. Check back along the wiring for a starter.
If you can access the ignition switch you could check for constant volts at the orange wire and for 12V on the yellow wire when the ignition is on. The yellow wire feeds the tail light and number plate light. There should be continuity from the ignition switch end through to the tail light.
My sincere apologies, mate. I gave you bad info in post #10. In Park, upper section and plate light come on. I don't know how I missed that before or perhaps something has reset? But on ignition, the upper and lower sections and the plate light stay off. I tried with the engine running as well, but no joy. On braking, upper section and lower section come on.
OK. That shows that there is continuity right through the yellow wire from the ignition switch to the tail light. I was looking at a 2017 diagram but realise that there is a mistake in it as it shows a connection between the tail light circuit and the dash. The 2015 diagram shows no such connection, nor do the Supersport diagrams which have similar wiring. So whatever switching happens with tail light / parking light circuit must be within the ignition switch. The switch has 4 wires, red from permanent 12V, red/white switched 12V to fusebox, orange from 5A lighting fuse and yellow out to parking/tail light circuit. I think the orange wire should be switched to the tail/park circuit in both ON and PARK modes, which would make sense or else it would be switched to the main 30 fuse. Wiring diagram is attached.
You will not believe this. Or maybe you will. About ten minutes ago, I decided to pull every fxxckin' fuse whether it had anything to do with lights or not. Pulled a 5A fuse listed as "Control Unit" in the manual. Blown. Replaced. All back to normal! Thanks very much indeed to everyone who helped, but especially to Derek who went above and beyond! Thank you mate. I owe you a pint. Or two!
