Brake warning light

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KIMDEB

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Fellow Frogger
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Feb 15, 2002
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Tamworth NSW
Regarding the late model R12 (1.4 / Virage) instrument panel.

On the right cluster (at about 4 o'clock position) is the brake warning light. This normally illuminates with ignition on, then flashes and extinguishes after engine start. Presumably, the flashing is a part of the circuit self-test on the brake fluid reservoir level, and the master cylinder dual circuit pressure switch.

Recently, this light has remained illuminated at all times. Removal of the terminals to the reservoir and master cylinder do not extinguish the light. The printed circuit appears OK, as does the diode (although I am not sure if the diode is actually a part of the brake light circuit).

Does anybody have any suggestion for correcting this problem? Removal of the globe will not be considered as an option!!

Cheers,

Kim.
 
KIMDEB said:
On the right cluster (at about 4 o'clock position) is the brake warning light. This normally illuminates with ignition on, then flashes and extinguishes after engine start. Presumably, the flashing is a part of the circuit self-test on the brake fluid reservoir level, and the master cylinder dual circuit pressure switch.
Kim.
Click to expand...



<SPAN style="COLOR: black">This is one warning light that you want to work properly. But self-test, HMMMMM are you sure this is supposed to happen, it sounds a bit odd. The Virage wiring is pretty simple and it would be unlikely to have a test circuit for the brake warning light but I could be wrong. There's nothing in any R12 wiring diagram that I've seen that would do this. Do you have a wiring diagram?
 
OK, This one should be relatively simple to analyse.

The 12XL and early 1.4s had a combined brake fail and handbrake warning light, ie one light suits both purposes. This has a little picture of a foot pedal on it (some depict a handbrake). Those 12 1.4's and Virages built in late 1976 onwards have two separate lights, required by ADR's at the time, one light depicted "Brake Fail" the other "Hand Brake".

I would say that your car is an earlier version with the combined light and that the handbrake light wire has either chafed through (the wire runs under the seat frame and can be crushed) or that the plastic surround on the wire has perished where it connects to the spade on the light switch at the rear on the handbrake. Also check that the light switch is not broken. Also, if the original two piece handbrake bracket has been replaced at any time with a one piece pattern aluminium bracket, this can also short on the wire causing the light to flash or remain on, or the light switch alignment within the new alloy bracket can cause the light to flash.
 
Hello Simon (& others),

Thanks for your replies.

As stated at the beginning of the thread, it is a late model Virage (1978 actually). There are two separate warning lights - one covering the handbrake ON function, and the other the low brake fluid / master cylinder pressure drop switch. The handbrake circuit is working OK.

I do not have a wiring diagram which covers the Virage models, only the earlier TL/GL models from an original factory workshop manual.

As you mentioned, it should be easy to diagnose. I have the instrument cluster out at present to have the speedo repaired, so any issues re wiring looms, printed circuits etc can be dealt with during this time. As you know, the printed circuit incorporates multi-pin push-on loom connectors, which seem fine at first inspection.

Any other suggestions will be welcomed. Does anyone have access to the later model wiring diagram??

Cheers,
Kim.
 
Out with the multimeter then.

Something is grounding where it shouldn't, has brake fluid stripped some insulation from the wire somewhere perhaps?

Did late Virages have "worn brake pad" sensors on the front discs?
 
Kimdeb, you mention that removing the terminals from the reservior etc does not extinguish the light. I would be suprised if it did because the failsafe circuit is designed to light if anything goes wrong in the brakes or wiring.
If it's not a fault in the level switch or pressure switch, it can only be a bad connection or short circuit in the warning system.
 
Kim,

I have a owner's handbook from a Virage which has a circuit diagram in it and a workshop manual with the diagram for the 1977 R12 (they're actually the same), but for your problem it's useless. The brake pressure switch or brake fluid level aren't on the diagram.



Ren
:cheers:
 
Thanks for the replies people,

There is no low pad warning system fitted to the Virage, so that rules out possible electrical / brake attention in that area.

However, I will keep searching and checking this weekend, and if successful, will post the findings. Meanwhile, anybody that stumbles upon the answer, please let me know.

Regards,

Kim.
 
You may not have wear indicators fitted in your pads but could a ire still be provided for this? this may have shorted somewhere on the suspension components - worth a look perhaps? - I have had a cracked wire short like this that gave an similar problem signal as yours - not on a 12 but 504

Regards,
 
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