1198 Rear Light Not Working

There's one under the seat

 

The connector is the same one for the tail and brake lights, so it couldn't have come apart if the brake light is still working.

I'd start off checking fuses and then get a multimeter on the connector.

 

You'll have 3 connectors like in the picture below. The indicators are marked 'DX' and 'SX' iirc. The the 3rd one will be your brake / tail light connector.

 

The indicators are the singles hanging down in the above picture. The rear and brake and earth are all in the 3 pin connector facing rearward. I am sure that secondhand lights are easy to get, I have a spare here and so does everyone who has fitted a TST tail light. There are also many cheap copies on ebay from China.

 

Nope and it's an MOT fail to boot

 

As @Tobytyke said errrrr No!!!

So if its only coming on with the front then its probably something to do with connector or brake light switch at the rear brake

Looks like they both get power from fuse #3, so its not that

Red/Blue is the power
Green/Red the signal to the lamp

This is from a 1098 diagram but sure it will be the same

I'd check you have power at the connector and then test the switch is working and obviously clean any connectors that are dirty

Good Luck

John

 

Amazing how quickly you forget Bob. I only wired mine back up last year.

Is the 3rd tail for the number plate light then? That would make sense.