2 replies to this topic

[HNSGEQ]

Hi All,

My LX sedan that I'm restoring and converting to an SLR5000 Tribute started life as a 4 wheel drum brake car with a drum brake proportioning valve and a single pole proportioning valve switch, ie the wiring on the proportioning valve has only a single plug and single wire.

 

I'll be converting the brakes to HQ discs and HQ drums and have bought a proportioning valve from an LH/HJ which also has a single terminal on the proportioning valve switch.

 

I'm probably reading too much into all of this but will the warning light with the single terminal that runs from the proportioning valve work okay on my LX SLR cluster or do I need to change the switch and wiring to a dual terminal switch? 

 

Would anyone have any thoughts on this?

 

Thanks in advance all,

George

 

[ls2lxhatch]

The dual pin brake fail switch was fitted to comply with ADR31.

 

Pre ADR31 cars used the same globe for the handbrake warning light and the brake fail warning light. To check the globe is working all you had to do was put on the handbrake.

 

ADR31 required a separate brake fail light and handbrake light.

 

To test the globe is working a second wire was connected to the brake fail switch. If you look at the pins in the brake fail switch you will see they are joined together. The first wire goes to the globe and the second wire is connected to the ignition switch as a globe test circuit. When the ignition switch is in the start position it earths the second wire and the brake fail globe lights. If you disconnect the wire from the brake fail switch then the second wire is no longer connected to the brake fail wire and the globe will not light when the ignition is in the start position.

 

Following the letter of the law if you have ADR31 on your compliance plate then you are required to have a seperate brake fail light with a test circuit. Whether or not anyone will notice or care is anyone's guess.

 

You could just run a second wire to the single pin switch (or connect the test circuit under the dash). This would work the same as the dual pin switch, the only difference is that the test circuit would still light the globe even when the wire not connected to the brake fail switch.

 

The brake fail switches are not interchangeable. See this post for more details.

http://www.gmh-toran...ng/#entry911759

 

It would be a lot simpler to just buy dual pin proportioning valve.

 

 

 

 

 

 

[HNSGEQ]

Thanks for the informative reply LS2LXHatch. Much appreciated.

 

My LX doesn't have ADR 31 on the compliance tag and my SLR cluster has a "common" brake fail and park brake light so I can, and should, use a single switch on the proportioning valve.

 

All good and thanks again,

George