Brake Pad Wear & Coolant Level Sensors

[Astra Dan 0]

My 1989 1.6 GTi has the brake pad sensors and wiring intact and looks complete. I've just replaced the coolant level sensor with one from a scrappy. It reads a short across the terminals when upside down, and open circuit when right way up, then short again when it's in the water bottle with the correct amont of water in. I assume this is correct.

 

But with either the brake pad or coolant sensors unplugged, I get no extra lights on the dash. Does the brake pad sensor use the handbrake light? Should the STOP light come on too? I assume the light with the container with lines across is low coolant, should this light up with the ignition to test the bulb?

 

Any info on how these systems work would be a great help. The Haynes book of lies is no use at all!

 

TIA.

Edited December 19, 2007 by Astra Dan

[pug_ham 244 3 Cars]

The low brake pad sensor should have a seperate symbol in the top lhs of the speedo.

 

http://www.205gtidrivers.com/articles/m-instrumentpanel.html

 

The low coolant sensor should only light up on the dash when you don't have enough coolant in, no test system built in.

 

Graham.

[Astra Dan 0]

Surely if I lift the sensor out of the water it should come on?

 

Thanks for the reply.

[steve@cornwall 100]

I think the brake wear warning comes on when the sensor earths to the disc due to pad wear, so earthing the sensor should light it up. I doubt very much if they ever light up for the proper purpose, though as you should feel that something's amis long before this !

Edited December 20, 2007 by steve@cornwall

[pug_ham 244 3 Cars]

I think the brake wear warning comes on when the sensor earths to the disc due to pad wear, so earthing the sensor should light it up.

Thats also how I understand the brake wear warning light to work but usually the wires have broken long ago & the sensors are useless if you have grooved discs on.

 

Surely if I lift the sensor out of the water it should come on?

Yes, it should if the sensor actually works.

 

Graham.

[Astra Dan 0]

Well my test of checking turning the sensor upside down etc should have proved that I guess. I'll try grounding the brake pad thingies oot.

 

Ta

[Phil H 16]

Do the wires that are attached to the top of the suspension strut have anything to do with the brake pad sensors?

[jackherer 543]

Do the wires that are attached to the top of the suspension strut have anything to do with the brake pad sensors?

 

Yes they complete the circuit to ground. Without those the struts/hubs would be electrically isolated from the rest of the car due to rubber mounts.

[McPikie 0]

Wondered why I had some earth points there and some dodgy wires tied up, lol