Brake light not working - a few questions

Hey everyone - I just checked my brakes and found that the brake light doesn't light when I apply either the front or rear brake, and I was hoping that the community could help me answer a few questions:

1. I removed the fender and second light from my bike a few months ago (pre- and post- photos are attached). When depressing the brakes, do both lights light up? Or just the lower light (that I removed)? If I removed the brake light, it would make sense that it would light up. I don't think this is the case but thought I'd check. If anyone can check their GRiSO and let me know what lights light up when pressing the brakes I'd appreciate it.

2. If the main rear light also acts as a brake light, I think I need to check the front and rear brake light switches. Where can I find those?

3. Are there any other suggestions you guys have?

Thanks for your help.

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The light (16) you still have includes the stop light
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The two Stop switches (19) & (20)
I don't remember where the switches are, sometimes they use a mechanical switch operated from the lever, other times they are a pressure switch operated by the brake fluid, the front switch should be easy to find, its between the RH lever and the front discs.
When you find a switch you should have 12 Volts on one terminal via Fuse 1 (with key On), the other will only have 12 Volts when you apply a brake.
I think the connectors under the seat at the rear is where I would start looking for a disconnected wire.

BTW, I like the look of your bike with the fender removed and after-market pipe.

The back & front brake light switches are both mechanical and totally separate so I agree with Kiwi Roy

Kiwi_Roy wrote:

I think the connectors under the seat at the rear is where I would start looking for a disconnected wire.

Its a thin three pin plug

Good luck

Front switch is on the handlebar lever perch and has two wires going to it. Rear switch is down by the foot brake lever and as suggested, has a connector that joins to the loom on the RH side under the tailpiece up by the pilots part of the seat.

It's rare for both of the switches to go out together or both become disconnected although obviously not impossible. The culprit is more likely to be either the wiring to the light unit at the rear or the light unit itself. Sadly the light unit is pretty much impossible to disassemble but the actual LED's are unlikely to fail so the problem is most likely in the light unit wiring or plug or the wiring in the loom.

OK - here's an update. I checked all fuses, and nothing was blown. So at that point, I took my bike in to a friend of mine and exceptional Guzzi mechanic, Joe Walano, the Guzzi Doctor (https://www.facebook.com/theguzzidoctor/)

Anyway, the front brake switch had a short, so the system always had the brake lights engaged. It wasn't that the brake lights wouldn't work, but more that the brake lights were always on. When Joe disconnected the front switch, the brake light went back to where it should be (as a tail light with lower brightness) and when he depressed the rear brake lever, the brake light worked properly.

He's getting a replacement part now.

Thanks for all of your help.

I've seen that before on a group ride but can't remember which Guzzi.

 I had sprayed some lubricant on my brake lever and some of it must have gotten on my switch.  No light just on hand use.  Luckily Muley had some Deoxit in his kit and we fixed it right up.

I had a similar problem. Bought a new taillight unit. Still no light going on. Bought a schematic and had it enlarged to 3' x 4' and tried to trace the problem clearly.
IT WAS THE NEW UNIT!!!! IT WAS WIRED BACKWARDS. BLACK WAS WHITE AND WHITE WAS BLACK!!!

TRY LOOKING AT IT THAT WAY!