TR6 Brake Warning Light Stays On

[Gerry M]

I have a 74 TR6. My brake warning light (and oil pressure light) come on when I turn the ignition 'on'. I believe this normal. But they stay on after the car is started and don't go out until the ignition is turned off. The brake fluid is full, the brakes have plenty of pedal and feel normal, and the oil pressure switch wiring looks OK. What could be causing the lights to stay on?

 

[dklawson]

The wiring diagram for your '74 is in the PDF linked below from the Advance Auto Wire web site.
https://www.advanceautowire.com/tr2506.pdf

It looks like a failure of the oil pressure warning light switch (or if you really have no oil pressure) will cause the problem you are experiencing. If you unplug the white/brown wire from the oil pressure switch with the engine on or ignition on and the lights go out, confirm you really have oil pressure. If the pressure is OK, consider replacing the switch.

 

[poolboy]

Yeah, it's not a brake problem. If it were, the OP lamp would not be lit and the BRAKE lamp would be brighter

 

[Gliderman8]

I had a similar the problem when I first got my '76 TR6. The oil light stayed on despite the fact that the pressure gauge showed I had plenty of oil pressure. The light stayed OFF until I started the engine and then the light stayed ON.
What I found was that the previous owner had the wires switched on the oil pressure switch. He had the White/Brown wire and White/Purple wire switched on the oil pressure switch. Essentially, once the engine started the White/Brown went to ground to close the circuit.