Is it also the warning light for brake pad wear?
No . The only sensors near the wheels are not near the brake pads. I suspect they are for measuring wheel speed only. I didn't get home from work early enough to check the other bits with multimeter. Will do those in morning .
(Thought I posted that last paragraph last night but not sure it went up)
So to summarize. The handbrake disconnects a cable that connects to earth........ when working normally that is . Right now Disconnecting the cable has no affect on the " handbrake light " (braking fault warning light according to Haynes)
The reservoir completes a circuit when fluid is low. Mine is working fine from what can be seen .
I tested an empty on and the two pins made an audible sound when touched. For what it's worth I found out today that the connector that connects the two cables to the reservoir was faulty. The negative earth cable side is broken inside and no continuity there from connector to the cable.
There is very low voltage from the second white cable on the same connector to the chassis.
That's the non earth cable that normally goes to the reservoir. It comes from the fuse box area of the van. I have a donor van to rip apart and find out its origins lol. Time is scarce these days unfortunately and this is what happens when you fall off a cliff after living on a slope for so long.
I have lost a fortune in days off work but mechanics in this area are of little use
Is it also the warning light for brake pad wear?