Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

My NSX is JDM so it has 4 x brake lights.
Each are rated at 27W so over 100W and about 8A passing through this small terminal when the brake pedal operated when the alternator is regulating the voltage around 14.0 – 14.5V.

I switched to P21/5 in the past as it was not easy to find Bay15d 27/5 in UK so lower current consumption but still, fair amount of heat could be generated at the switch.


With the European spec NSX, the brake light is rated at 21W and there are only 2 of them.
So, most likely, the brake light switch would survive much longer.


After looking at this melted switch, I thought about using LED bulbs for the brake light.

My gauge cluster is refurbished and no worries of cabin fire caused by the capacitor leakage.

The use of LED brake light bulb will require disabling the lamp failure detection circuit.

There are few signs of capacitor leakage and one of the most common one is the false 'BRAKE LAMP' warning.

Even after disabling the failure detection circuit, you will get this false warning under one condition.

However, you won't get it under another condition that is not great for spotting the gauge failure.

Therefore, by disabling the failure detection circuit, you'll lose part of the precious first sign of failure that could lead to the cabin fire.

For this reason, I don't recommend disabling the failure detection circuit without first refurbishing the gauge cluster.


From different point of view, the switch survived more than 170K miles and nearly 29 years with over 100W power consumption so why not just get another OEM switch.

While waiting for the delivery from Japan, placed order at Rockauto as a backup.

It still takes extra week or two for the delivery from Japan and who knows what will happen with all these industrial actions....

Some airmails from Japan took more than 1 month to arrive and even the Christmas cards posted within UK last year only arrived well into the new year.






While waiting, had to make this faulty switch work so temporary fix applied.
Trimmed off the melted portion and reconditioned the burnt contact.
Not great but it does the job for a temporary fix.

Reassembled and tested so back on the car.








And the delivery from US was really fast and got the aftermarket one.
Ordered two of them.
They are both Standard Motor Parts Intermotor SLS139.

For some reason, one was made in Italy and the other was made in China but both felt good quality.

The top one with the white connector is the OEM one from TEC.






The connector on the aftermarket one is slightly different from the OEM one.
It has additional recess, unlike the OEM one.







However, the mating connector on the chassis loom has the exact recess so no problem.
Same arrangement as the 4pin relay connector, etc.

While waiting for the delivery of OEM one from Japan, installed this aftermarket one for now.



And just when I thought I treated my NSX well, suddenly, I started hearing intermittent rattling noise from the front bumper area.

Switching On and Off the A/C stopped the noise so it's something to do with the condenser fan.

While investigating, suddenly the noise stopped and no more L side condenser fan so I thought the motor just seized and the 10A fuse was blown.

However, the fuse was fine so either the brush got completely worn out or the stator/rotor got damaged.

Seen many fan motors failed on low annual mileage ones due to build-up of rust inside the motor but not on the frequently driven one like mine.

I always use A/C throughout the year so most likely, the brush worn out.

If L-side is gone, the R-side won't be far off.

I hate removing this motor and shroud without extra hands while keeping the front bumper in place.

Will place parts order for just 1 motor (not cheap) any way while it's still available.

The original motor manufacture Mitsuba is not in good shape.....

Will try finding the replacement brush to refurbish existing two motors as the DIY project.



And also started getting bearing like squeaking noise only at the fireup when temperature is below freezing.
No noise once warmed up or temperature above 3degC.

Probably the bearing at the A/C idler pulley or possibly one of the alternator bearing is at the end of its life.

Have spare bearings so will look into it later.



Going to be very busy year….

Kaz