1991 900ss electrical question

Hi everyone. I just took delivery of a 1991 white frame 900ss. I’m smitten!
Have got it in the garage now giving it the once over. The speedo stopped working when the previous owner was riding it to our hand over point. No problem, broken inner at the wheel, new cable on order.
BUT, I have an odd problem. The rear light does not work but the brake light does and from what I can see the brakes are operating both filaments in the bulb. Checked the wiring under the seat including the connector block and all seems ok there. Any ideas where else I could search.
The other problem is that when I operate the front brake the light comes on but does not go out unless I waggle the lever about. Obviously I am probably riding along with the brake light on most of the time! Any suggestions for a fix most happily accepted!

Its a lovely bike and it took me back 30 years to when I had an 860GTS. It may have belts but the character is just the same!

Hello Zuff.
Sounds like the bulb has been forced in at the wrong angle or it’s a faulty holder or bulb?


Thanks Kevin. The plot thickened when I discovered that the park light function on the ignition operates the bulb correctly. So my suspicion is with the left hand switch. Will investigate and let you know.

After a lot of fiddling I suspected the fault lay with the wiring in the ignition barrel.
Haynes manual said special bolts hold it in requiring a Ducati dealership to remove.
Stumped. So called an auto electrician who came to the house and agreed with my diagnosis. The he discovered that the hidden security bolts had been replaced with plain allen bolts, had the barrel off in no time and a broken wire discovered. A quick bit of soldering and Result!
Best £80 I ever spent. If anyone in Wye valley area has a an electric problem, PM me and I will pass on Daves contact details. Hes a top man!

Well, sorted in the end, that sounds like an odd fault and a bugger to find, hopefully now ll OK.