Datsun Roadster Forum-311s.org

I’ll likely have some elementary questions as I figure out this new car….apologies.

Can someone tell me what this knob does? Is located on the center console and pulls out (one position). There’s a red light to the right of the steering wheel that illuminates but it doesn’t seem to do anything other than illuminate the light.

Anyone have more info?

As far as I know, it just tests that the brake failure bulb is working. I converted mine to turn on my audio system and the brake bulb is now my alternator charge light.

Thanks, Matt. An interesting factory option for sure .... is there a brake pressure sensor, low fluid level sensor or something that tells you the brakes are failing? What would trip the light?

Yes, brake pressure sensor, on the firewall near the ballast resistor.

S brake manifold

viewtopic.php?p=330315&hilit=s+brake#p330315

Thanks for the link to that - much easier to understand the concept and intent.

The most correct definition of what the light represents when not in test mode via the s/brake knob, is a brake imbalance warning. What the block sensor is showing is that one side of the hydraulic system is not fully functioning or failed. The knob is only there to verify that the bulb is working and lights on and goes off when tested.
Dave