I have been having the warning light coming on intermittently. Then it would come on when I turned the steering wheel. It's now on permanently.

I had the ends by the brakes joined together and taped up since buying four years ago, so assumed I would redo it. But it didn't work - the copper wires are black and presumably badly corroded and the light stays on, so I'm thinking about getting a new cable (£70).

But I don't know where the wires go to. They join into a big bundle that goes through the firewall at the far right end, but I haven't got further than that. From the photo of a new one, they appear to be only a few inches longer than that. Does anyone know how to access the hidden end or what they connect to?

Thanks for any tips.

The wire is just a ground contact, when the brake pad wears down to the contact it then grounds from the brake disc to alert you to worn-out pads.

 

It sounds like the wire has chaffed and is now touching metal, find and insulate the bare part or simply cut the wire further up to where it won't cause nuisance alerts but be aware that low pad thickness will go without warning.

Yes I think the wires to the pad sensor are either broken or corroded, but I'm not sure where. I've stripped the pad sensor cable almost to where it joins with the ABS sensor cable. They are grouped in with the ABS sensor cable and together they go through the wheel arch grommet and then join a bundle that disappears through the firewall sort of behind the glove box. I want to know how I might access the other end of the cable to see if it can be repaired or needs to be replaced ie what I have to dismantle to get to it.

For £70 on a 15 year old car... snip!

 

Disregard my previous statement re single wire ground, with 2 wires it will require the wires to short across the disc to activate the idiot light.

Edited 27 April, 20233 yr by MicMac

Well I decided to have another look at this problem. I have removed enough stuff around the battery to see that the wires join a big bundle and head off through the bulkhead and into the mass of wiring behind the glove box. You cant really see the cable in this photo - it's on the hidden side of the taped up bundle.

I also cleaned up the ends of the cables and joined them, but the warning light still shows.

 

Is it possible that a fault code might be stored leading to the warning light staying on?

 

If not I guess I could extract the two wires from the bundle, cut them and twist them together, but it's a pain if that doesn't solve the problem!

Any thoughts anyone?

The brake pad wear indicator is designed to light when the system goes closed-circuit.

 

Cut and insulate the red and yellow wires and the indicator will extinguish.

The yellow wire continues into the cabin, changing to yellow/green at some point, and ends up at pin 22 of the 36-way connector at the instrument cluster. The red wire should go to earth. When pad is thick enough, these are connected, so shorting is the right thing to do. Earth the wire going into the 36-way, to see if that works.

If not, are you 100% sure the warning light is for pad thickness, not e.g. brake fluid level?

Thanks Pete,

I took the glovebox off, and decided not to mess with anything there, so cut the wires in the engine bay and joined them.

 

 

The warning light then went out, so I guess the fault was the corroded wiring near the connector. All good now. Case closed.  Thanks all.