Brake light is always on

[MrTwo]

I came home from work today and noticed that my brake light was still on when I got out of the car. I turned the car back on and hit the brakes a couple of times with no luck, I also turned the parking lights on / off and it is still stuck on. I ended up pulling the fuse for the brake lights so I don't drain my battery.

Any ideas on what could be causing this problem?

 

[smoore]

brake light on the dash or brake light in the tail lights?
brakelight on the dash would mean low fluid or your e-brake switch needs adjusting or you have the e-brake up alittle.
if it is the rear brake lights that are on constantly on that would be weird. Proberly the switch for the brake pedal under the dash went bad. when you step on the brake it pushes alittle button in. Go under the dash and try to unplug that and see if it helps. the you'll know the problem.

 

[Ojas]

Check the brake light switch at the pedal (see attached diagram). Press it in with you hand. If the brake light turns off, adjust or replace the switch.

 

[D'Ecosse]

http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf

Go to page 1191

 

[MrTwo]

brake light on the dash or brake light in the tail lights?
brakelight on the dash would mean low fluid or your e-brake switch needs adjusting or you have the e-brake up alittle.
if it is the rear brake lights that are on constantly on that would be weird. Proberly the switch for the brake pedal under the dash went bad. when you step on the brake it pushes alittle button in. Go under the dash and try to unplug that and see if it helps. the you'll know the problem.

Unfortunatly it is the tail lights, they are on just like when you hit the brakes not when the headlights are on.

Thanks to everyone for the great advise, I am going to the parking garage to do a headstand in my car right now

 

[MrTwo]

Ok I found out what the problem is! (Thanks for the excellent diagram Ojas!)

The brake light switch is a normally open style switch so when the brake pedal is depressed it turns the switch off and lets the brake lights come on. The section of the bracket that the switch hits is plastic (small hole filled with a plastic cap.) It looks like the plastic became to brittle after 15 years and finally crumbled. Can you buy these plastic caps without buying the whole switch assembly? If not I will probably try to fashion a piece of metal to go in its place.

Thanks again to everyone for all the help. I'm relieved to find out this is a simple fix!

 

[D'Ecosse]

The brake light switch is a normally open style switch so when the brake pedal is depressed it turns the switch off and lets the brake lights come on....

The normally open switch when operated will turn the switch 'ON' and complete the circuit to turn the lights on.

Buy a new switch assembly - it's $40 from a discount Acura parts supplier!

 

[garyn]

If you can't find a replacement plug, try using a plastic rivet or a nut and bolt with a rounded head. The hardest part is getting under the dash! Good luck.

 

[MrTwo]

If you can't find a replacement plug, try using a plastic rivet or a nut and bolt with a rounded head. The hardest part is getting under the dash! Good luck.

I just got back from Goodson Acura and $3.04 later and I'm back in business I bought a new plug from Acura instead of having to buy the whole assembly.

A big thanks to everyone for the help and advise!

 

[Joe Manny]

brake light on the dash or brake light in the tail lights?
brakelight on the dash would mean low fluid or your e-brake switch needs adjusting or you have the e-brake up alittle.
if it is the rear brake lights that are on constantly on that would be weird. Proberly the switch for the brake pedal under the dash went bad. when you step on the brake it pushes alittle button in. Go under the dash and try to unplug that and see if it helps. the you'll know the problem.

Thanks for the insights on the hand brake indicator light. I am going to check the brake fluid level. But in case it is the e-brake switch, how difficult is it to adjust?

 

[B. Kotcher]

Thanks for the great info, guys. My '93's battery was mysteriously stone dead and when I recharged it I saw that the brake lights were stuck on. I pulled the fuse and came here to NSX Prime where you guys have all the answers, ah...

Sure enough, pieces of my pad were in the footwell. I ordered a replacement from Amazon and the next day dove under to effect the repair. Here's a video where someone describes the operation:

.

Well, I'm 6'-0", 217 lbs., and 65 years old so hardly small and spry and I suffered under there for 20-30 minutes trying to squeeze the bugger in. I was about to give up and have my shop do it when I finally did it. The trick is not to try to insert the cone into the hole because then the blockish "button" end will not be able to get past the extended plunger. Instead, wedge the "button" end under the plunger, then push sideways and the "button" will wedge the plunger into the retracted position. Then there's enough clearance to barely swing the cone end into the hole (if you can keep the bugger from popping out in the process...).

The clutch pad must be about to go, too, so I'll have my shop do that at my next service. Plus I'll probably replace both with genuine Honda parts because who knows the quality of what I bought on Amazon...

 

[dede1]

Thank you all for the info and descriptions. I found the end of the button on the floor as you suggested. I will order the new part. While waiting to get the new part and wanting to drive the car, I found a small flat key holder, an inch and three qtrs. long and an inch wide, by i/8 of and inch thick. You can buy these for 50 cent a piece at lowe's. It fit nicely into the space for the button. When inserted the lights went out. Step on the brake and it falls out. Low and behold in a utility room draw I found two sided tape. I taped one side to the piece of plastic and the other to the brake plate where the button fits. Not a final fix but it gives me the car while I get the new part and have time to put it in.
Can't say enough about the NSX forum. I've had my 1995 Red NSX pretty much stock except for wheels, short gears, and dual clutch for over 20 years. Time and time again, every problem I have had I can find solutions on this forum. Worth it's weight in Gold.