4 replies to this topic

[123OUC]

Hi all,

I have got the "universal" GM disc front drum rear proportioning valve. It came with a warning switch that is single pin. My existing wire is 2 pin. can these be spliced and joined into one?

cheers in advance

ps.I have attached pictures to help out

Attached Files

•  proportioning valve setup.png   111.08K   14 downloads
•  bronco-proportioning-valve-diagram.jpg   84K   7 downloads
•  bronco-proportioning-valve-diagram.jpg   84K   4 downloads

[Bigfella237]

Easiest thing would be to buy or find a 2-pin switch, I haven't looked but I wouldn't expect them to cost very much?

 

EDIT: To answer your question, no, if you join the wires the brake warning light will be on all the time.

 

They were two completely different systems, the early 1-pin switches earthed-out the wire to turn the light on, the newer style connects a positive feed to the light to turn it on.

 

If you mix 'n match you will only blow fuses if the switch trips.

Edited by Bigfella237, 22 March 2018 - 12:11 AM.

[Dr Terry]

Not quite correct Bigfella. The 2 wires can be joined & it will all work fine. All of these wires are on the earth (-ve) side of the globe circuit.

 

The 2-pin connector on the factory switch has its pins joined in the socket. It is a system of self-checking the circuit.

 

Each time you turn the ignition switch to the start position the brake fail light should light up to show that the circuit is complete & the globe is OK. Many people used to leave the pressure switch unplugged if the pressure had been lost but the switch hadn't been reset. With the plug disconnected the globe didn't light up on crank to show the circuit was faulty.

 

If you join the wires together to fit a single pin switch, the light check function will still work OK.

 

For rego purposes the light must come on in the crank position, much like ABS & airbag lights do nowadays.

 

Dr Terry

[Bigfella237]

Apologies, I looked at the wiring diagram supplied, saw the wire coming from the ignition switch and wrongly assumed it was a positive feed. Serves me right for posting when half asleep.

[123OUC]

Cheers for the reply guys.

Appreciate it