Hello, I know this was covered before and followed the threads (very useful). Happened over course of 3 days. Handbrake light would eventually turn off when hand-brake released but now on constant.

-Checked and replaced lever switch, some WD40. It is touching ground when lever released but light stays on.

-Unclipped switch from lever. Voltage test between switch and ground gives about 5V.

-Fluid in reservoir, full.

-Continuity test at reservoir level sensor gave no signal (think that's correct when reservoir is full).

-Voltage test at reservoir level sensor connector plug gave 12V

-ABS fuse sound. Removed and tested that and reset to turn off ABS light which came on when fuse was taken out.

-Haynes manual doesn't give much this and nothing on the wiring.

Can't think of anything else to trouble shoot. Any help, much appreciated. Many thanks.

Just ran diagnostic. No codes appearing either. Perhaps failed solder behind cluster?

Unclipped switch from lever. Voltage test between switch and ground gives about 5V.

 

Don't think thats right. Need to measure resistance from one side of switch to chassis rather than voltage. Other side of switch should go to one of the modules. 

Question:if you disconnect the switch, does the light go out? 

HI, sorry for late response.

Light stays on whether switch is disconnected or not.

Since replaced all four discs and pads (needed doing anyway). Even replaced the hubs and ABS sensors. ABS light off, no problems there.

Replaced brake fluid reservoir just in case it was the switch giving a sporadic connection.

Brakes a bit spongy but I'd say I need to bleed the system, next job.

Master cylinder seem fine as I pumped pedal until firm with engine off and there was some give in it when I started it up again.

I've looked at the wiring diag in the Haynes and it looks like the switched end of the hb switch goes to an electronics module called transmission control unit (!?) gawd knows where that is! But if you can find it, unpug it and check the plugs/sockets for corrosion/overheating. However the live side of the hb switch comes from a 15 amp fuse! So I'd expect to see 12volts on that wrt ground. So once again trace out the feed wire from fusebox to the hb switch and meter it out for high resistance... easier said than done! 

Thanks so much for that. Weather's nice so going try that and let you know how I get on.

Hey Nicam,

Think you might be onto something, found transmission control unit aka general control module aka ECM.

Four large connector plugs. Tracing a Bk/Rd wire to two of them. Disconnecting them one at a time. HB light has started to flicker and occasionally turn off so I think I'm disturbing something. Would like to try a voltage test but the way the plugs are made it's difficult to see what wire goes to what pin. Hope it's not the ECM 🤢.

 

Ok, removed all 5 connector plugs seeing as I was down there. Checked for corrosion, bit of electrical cleaner spray. Plugged all back in. So now hand-brake light goes off after a 20 - 30 second delay.

I think that rules out ABS, ABS sensor, HB switch, fluid- reservoir level and level sensor and pads.

So near and yet so far.

Do you want a pic of the Haynes circuit page... I'll try to pm you with a pic.. 

Yes please. At least I can start putting back all the centre trim and console.

Couldn't find a way to pm you a picture, so hopefully this doesn't upset the mods by posting it here instead.