Can someone please confirm what actions turn the Brake Warning Light on? Mine keeps coming on intermittently and the wiring diagram is incomplete for the brake warning light circuit?

Brake fluid is at the max level?

Assistance appreciated.

Woz

 

My brake warning light works for the hand brake. Disengage the hand brake and it goes out.There is a micro switch at the bottom of the hand brake mechanism.
I have 2 wires connected to the master cylinder cap but they don't seem to do anything, plugged, unplugged or shorted together does not make the light come on.
Could be different wiring for different markets. I have a black and purple wire from my ignition switch that took me months to discover was for a US market warning buzzer, When I replaced the ignition switch it was not connected.(I spent hours looking for the buzzer under the dash)
One harness for multiple markets with unused wires not plugged to anything is my assumption....same thing, wiring diagram is incomplete for the purple/black wire on some daigrams but is there on the US models. Mine seems to be wired same as the Canada diagram, purple /black for the horn on the steering column. I was trying to connect my wire to the horn circuit only to cause all sorts of other problems.

 

My car is an SIII USA version.

1. A float in the brake fluid reservoir. Contacts to indicate level. Brake light on fascia responds, or did!!! Busted contact. Fix efforts failed. Disconnected. I rely on regular visual examination.

2. Indeed, a switch on the hand brake. I rarely use them. Not good at remembering to release them!!

3. When I swapped in the David Boger sourced NOS ignition switch I found a connector free. It belonged as a piggy back to the ignition switch harness. I connected it. It buzzes to remind me the switch is on!! Fine with me, but apparently not so much with the PO!!

4. I messed with the horn relay. success, it is a mess! Will I fix it? A long may be....

5. Moat of the wires in my engine bay are neatly wrapped one way or another. Not so with a patch near the battery box. I opened a prior neat wrap to fid a speedo wire. No luck. Son fussed!!!

Carl

 

Woz, you probably have the same brake fluid container as the 420 and the same low fluid float / sender. I think it must be the float / sender going bad.

If the container is full, disconnect it and see if it stops.

 

Carl, that was entertaining but Woznaldo has a Series 1.

There are two switches for this circuit: One at the base of the parking brake lever and another on top/inside of your brake fluid reservoir. The brake fluid switch is a cork (yes a cork) that moves up and down inside an aluminum tube. When the cork drops it connects your two wires on the top of the brake fluid container, and your light goes on. Primitive? Yes.

The cork inside mine had disintegrated after 48 years. I replaced it with a modified wine cork, but I'm thinking that the new synthetic wine corks would be better and I'll change it when I get around to it.

Like Jose, my guess is that your cork is on it's last legs and this is causing intermittent connections and a flashing light.

 

Like others, I rarely use the handbrake so it’s constantly been off. I can’t remember if I’ve already disconnected the brake reservoir float? I’ll check both in the morning and report back.

Thanks all.

 

I have owned my series 1 for 36 years. I think it was 35 years ago I disconnected to float in the brake fluid reservoir. The light only ever worked on the handbrake.

 

I disconnected the brake fluid level float switch and haven’t seen the brake light again! Looks like I’ll be looking for a synthetic cork!?