How can I annoy you today Jim?

[Jim Haseltine]

MoT time is rapidly approaching and knowing that my front brake pads are beyond their best (no pad warning yet though) and also knowing that my tester loves to find things that he can take the piss out of me for, I thought I'd change them.
The discs are near the end of their life too but rather than go the AP route just before winter I thought I'd throw on a set of OE pads to last until spring time.
So, change the pads, refitted the old wear sensors - they aren't good but aren't worn through completely yet.
200 yards down the road - pad warning.
So wheels off again, sensors out, checked them both, still got continuity, refitted them, test drove with no warning, reversed into my drive - pad warning.
There's nothing fancy (like a resistance check rather than a simple open circuit test?) in the pad warning circuit is there? Am I right to think I can cut the cables and jumper them near the connector?

[douglas96]

I wouldn't have thought so Jim, but I have heard of the wires rubbing through and breaking the circuit that way. Hopefully not but may be worth checking.

If you do decide to go the jumper method, check the resistance and depending on what it is put a resistor in rather than just connecting them together.

[IanH755]

It's a simple circuit for pad wear with an Open Circuit (wire breaking in the pad) bringing the warning on so you can just twist the wires together like you suggested to bypass the pad.

However the loom goes about 3ft and through 2 areas (arch to engine bay & engine bay to ECU) so you'd need to check the loom as much as possible in case there's any damage because, as you had pad continuity, it can't be the pad causing the issue.

[Jim Haseltine]

Thanks Ian. I'd just found one of your posts from last year that said much the same thing. As I've touched nothing other than the pads and sensors I'd put money on one of them being iffy. I'll have the wheels off again tomorrow morning and bypass the sensors. If I still get the warning I'll dig deeper.

[Jim Haseltine]

It was the left sensor. Although it tested ok yesterday afternoon, this morning it didn't. Looks like the wires had been close to wearing through and my fiddling had completed the task. The ends of the conductors had been touching so the continuity test passed so I assume something (like the driving I did last night) caused them to pull apart. I've cut the wires near the plug, soldered them and covered the joints with heat shrink.