16 replies to this topic

[hanra]

You might need to find another mechanic mate? Thats pretty picky!!! Maybe he is thinking of the oil pressure light?

[hanra]

The brake light only has two paths to GND. Via the handbrake switch or the brake fail switch. One of these points need to supply GND for the light to illuminate. Turning the key to IGN prior to START would not allow the light to illuminate.

[ls2lxhatch]

If you have a single pin switch on the prop valve then the light is tested via the handbrake (pre ADR31 1977). If you have a two pin switch on the prop valve then the light is tested by the ignition switch.

Point out to the mechanic that ADR31 is not on your compliance plate and your car was built before 1977.

Firstly, LX Toranas have 2 different versions of the brake pressure switch, but why do they have 2 variations ??

It goes like this. Early LX is wired the same as the LH series, where the handbrake light & the brake fail light are one in the same. This was before the introduction of ADR31 (for 1977) where 2 separate lights were compulsory.

The single pin switch was used on the early cars & the 2-pin switch was fitted to the ADR31 cars.

Ever since the EH series, Holden had been using a globe-checking system where the temp light was lit momentarily when the ignition switch was turned to the start position. It was only the temp light which did this, because unless the engine actually overheating the driver never saw it lit. The oil pressure light comes on every time the ignition is switched on, but before the engine is started, so it wasn't wired the same as the temp light. Likewise the brake light was tested when the handbrake was pulled on.

When the separate brake fail light was introduced, this same test facility was required. The brake pressure switch was wired with 2 pins which completed the circuit to the dash globe. If you look inside the 2-pin switch you will see that the pins are joined with a link. If the switch if left un-plugged, the dash light will not work, part of the fail-safe wiring. One of the wires goes to the dash light & the other to the ignition switch as part of the test circuit. To test the circuit, what you need to do is un-plug the switch & use a paper clip to bridge the 2 pins together inside the plug. Then turn the ignition to start, so the brake fail light will come on. If it doesn't find out why. It can only be the globe or the ignition switch. Once that is fixed, plug the brake pressure back in. If the light stays on, reset the switch.

Edited by ls2lxhatch, 18 October 2011 - 11:21 AM.

[Dr Terry]

I gather this is for an annual NSW rego inspection.

If it is, then the inspector is wrong !!

The only 2 rules that apply here are Rule 101.01 parts f & h:-

f) = Brake failure warning light doesn't comply (with ADR31)

h) = (if fitted with ABS), the ABS self test/failure warning lamp does not operate when the ignition is turned on, and the engine is either not running or the starter motor is engaged.

Ask the inspector to show you the rule in the RTA rule book or on the website, which he must.

If your car is OK then you can afford to push the point & even dob him in to the RTA if necessary. If your car is a bit 'iffy', then wire up a relay to make the light work on start-up to keep the fool happy.

I am an authorised inspector, so I know only too well how all this works.

Dr Terry

[Toranamat69]

The plunger in your proportioning valve most likely needs to be reset.

It may have triggered when bleeding the brakes or if there was an issue with your old brakes or there may be a current issue with your brakes.

Reset the plunger and try the brakes out and see if it triggers again.

[hanra]

yeh my engineer told me the exact same thing. He said the brake light needs to light up for a second after start up, and automatically go off.

Well if it's an LH or early LX, show em the circut diagram.....! It simply won't happen that way!!!!

[rodomo]

Later ign. switches supply the earth while cranking.

[S pack]

yeh my engineer told me the exact same thing. He said the brake light needs to light up for a second after start up, and automatically go off.

Well if it's an LH or early LX, show em the circut diagram.....! It simply won't happen that way!!!!

^^^ Correct. The combined handbrake/brake fail warning light will stay on until the handbrake is released.

[hanra]

Good one. Least your armed with this info in case there is a "next time"!!

[marko1au]

DR Terry,

              i have a lx torana that im rewiring ...... could you please show how to wire up the warning light to illuminate when the ign is on before starting please ...... i have the single pole sender fitted ......

 

                                                                                                                                                      mark