I'm replacing my wife's R50's front pads and rotors and sensor. But contrary to every single walkthrough I've found, instead of simply plugging in, the old sensor seems to be spliced into something else. What should I do? The new one just has a plug, do I need to be stripping and splicing?

 

It should plug into that blue connector. What's on the other end of that?

My guess is someone had the wrong part (with an other type connector) and made it work like this.

 

Right side of blue connector goes to steering knuckle. Left side of blue connector has spliced wires, one goes down to brake sensor, other goes up to front of car and into bundle going to headlights etc.

The plug on the end of the wire coming from the steering knuckle is the same as the one on the new brake sensor so they wouldn't go together anyway -- they're both female I guess? Looking at other pictures online I think they sent me the rear sensor by mistake. But even with the correct front sensor/connector I would still have the weird splicing issue.

 

Yep, i bet the connector broke and they just spliced it.

Here is that sensor talk.

https://www.northamericanmotoring.co...-car-side.html

 

Sure but then what about the wires from the headlight bundle? Presumably there is some reason they were spliced in. If brake sensor just connects to whatever's on the steering knuckle isn't that just a closed loop?

 

what wheel are we talking about?

looks like left front. at that wheel there should be two wires. one for speed sensor, one for brake wear sensor

did it get tucked or cut? follow the wire going away from the knuckle

 

is your brake warning light on at your gauges?

 

This is front left wheel. In my picture, the wire from the right of the blue (female) connector goes to I guess what you say is the speed sensor or at any rate to the knuckle. The wires from the left side of the male connector slotted into that blue connector go 1) up to a bundle coming from somewhere and going to headlight, and 2) down to brake pad wear sensor.

This pic might be clearer, the brake pad sensor is dangling, the wrapped bundle coming from above goes to the headlight in one direction and somewhere behind the front of the car in the other.



The brake pad wear light was on which is why I'm doing the brakes. Although I don't even know if the light was for the front or rear lol.

The confusing part for me is that from everything I've seen the brake pad sensor should just have the one cable to the connector, not branching off and also tying into that other wire run going to the headlight.

At this point I think I'll just give up on the pad wear sensor and do without since I have no idea what's going on there.

 

what color is the single wire? Just curious, if brown that would be a ground.

 

Looks black to me.

Here's the complete situation:

A is the sensor at the knuckle, B is the brake pad sensor:



This is a pic of the splice, with again B being the brake pad sensor, A being the knuckle sensor, and C being the bundle to and from the headlight:




And here is a closer look at C where it goes to the headlight and off to wherever (splice with brake pad sensor [B] at bottom of pic):

 

I'm thinking either

1) just tape off the old sensor and do without

2) cut the old sensor wire near the sensor, and cut the new sensor and just splice it to the old wire so I don't have to mess with the old mystery splice

 

Just so you know, A in the first picture is your wheel speed sensor.

The wheel speed sensor and the brake wear sensor are normally clipped in at the thing behind the arrow on your second picture.

I would do option 2 as this would keep the brake wear indicator feature alive.

Personally I would open up the loom a bit, buy the right plug and restore it to original again 😉 I don't think there is magic but just "accidental damage".

But I understand that's a bit of a hassle and it's not for everyone.

 

One issue is after stripping the jacket on the pad sensor, it's two tiny wires with no markings/color to distinguish one from the other.

 

Pretty sure it doesn’t matter which way you connect them.

 

normally there are two connectors (the blue thing in your pic), one for the speed sensor, which goes to the knuckle, one for the brake pad wear sensor, which goes to the brake pad (obvi)

they both live in the clip circled in the attached pic.

also in the attached pic, noticed that your ambient temp sensor is hangin out. that should be clipped into the front bumper (not a big deal but while your at it)

to find the brake wear sensor you will have to go digging

 

someone can correct me if i'm off

brake wear sensor, one circuit

speed sensor, different circuit

you can't put them on the same circuit

 

Correct. The brake wear sensor is really simplebreak the circuit, light comes one. You can even just twist the wires together to turn the light on the dash off.

 

That's what I don't get - if normally the brake pad sensor clips into the speed sensor, isn't that a closed loop with no wiring out to power or computer?

 

They dont clip into eachother! They should both have their own plugs which isn't true in your case.

It should look like this (although colors of the plugs don't match with mine)

 

LukasH is correct. one circuit for each.

your brake wear sensor circuit was cut at some point