Are your Nissan 300ZX brake lights not turning off? At the top of the brake pedal (with another at the top of the clutch pedal if you have a manual transmission) on your Nissan Z31 300ZX is a pair of rubber stoppers that contact the brake light switch and fully depress it. They look like this:
The two on the brake pedal are each part number 46584-S0100 (Amazon
Over time these become brittle and can break – you may have noticed pieces of them under your pedals right after your brake lights started staying on. Stick your head under the steering wheel and look at the top of the brake pedal:
A closeup of the area we are interested in on the brake pedal (no clutch in this car to show):
You can see the hole where one of the stoppers was in front of the closer brake light switch. The other one has been covered up by the previous owner in an attempt to fix the problem… though not with the rubbers that ought to be there:
Yep, that’s a hacksaw blade cut into pieces which had been glued across the holes. It didn’t work. If you look carefully in the above closeup shot you can still see one bit of the blade glued in over the upper hole.
Previous owner choices aside, depress the brake pedal to give you some room to work in and pop the plastic stoppers into the holes like so:
Once you release the brake pedal you should now see the plastic stoppers fully depress the brake light switch. Check your brake lights now – they will hopefully be turned off!
If that isn’t the only problem with your brake lights it may be a brake light control module located in the boot for later model Z31s – our 1984 Z31 doesn’t appear to have one – or it could be corrosion in some of the connectors beneath the carpet behind the front seats (got water in there recently, perhaps?).