lazy brake lights

[NO LIFT]

Brake lights on my '88 Carrera don't illuminate unless then pedal is pushed hard. Or maybe it isn't until past a point further in travel than I normally brake.

I am a light braker.

I suspect the brake light switches that go into the master cylinder. Is my suspicion correct?

I've had my '88 four years now and I instruct at several DE's a year. Should I replace the Master Cylinder as a precaution?

Input/advice/suggestions please.

Thanks!

[DRACO A5OG]

Yes, the two Brake Light Switches need replacing. Remember to depress the pedal using a piece of 2x4 against the seat to the pedal then remove switches, dab a bit of fluid on the end of the new ones and put them on. ( on your year pinch off the clutch hose line as well )

You will need to remove the carboard cover and fresh air vent to get to the back one.

No need to replace master cylinder unless you feel the need to.

Jim

[Brillo]

Probably the brake light switches. Although I found with mine, it was only a slight improvement.

[sparkle84]

It's normal that the brake lights don't come on until the pedal is depressed quite a bit. Note I said normal. This is a design flaw in this system. If they work when pedal is depressed deeply then the switches are fine. Replacing the master cylinder is irrelevant. There's a good thread on here somewhere about using a micro switch located on the brake booster so the lights activate as soon as you depress the pedal. I've been thinking of going that route because the way they work with the current system is < desirable. Shouldn't be too hard to find if you do a search.

Good Luck

[DRACO A5OG]

Sorry to say as a ex-developer of the fix. It is not normal. But agree it is a PAG flaw.

The issue is the Brake Light Switch (BLS) amperage is so that it causes an Arc in the BLS and overtime or even on first use if significant amperage, it builds a carbon deposit and/or melts the plastic inside , and as a result more pressure is need to actuate the contact, it at all.

My business partner and I developed a relay that cured this symptom and I believe several dozen of us Pelicans have it on their cars with out any side effects and proper BLS response.

Unfortunately, like the Brass Coupler bushings the demand was very low and we could not keep the small production line running to keep it cost effective. Sorry fellas my partner was the EE so he has the design. I no-longer speak to him

The problem with the switch at the pedal is that it may go out of alignment or need to be adjusted from time to time. Worse if debris get stuck behind it, NO BRAKE LIGHTS. Granted before the pressure actuated BLS, manual was the standard but it also had it's own issues as stated above.

The only alternate is maybe a low pressure BLS but it will not cure the "arching" of the contact from the high amp output of the system.

My humble 2 cents,

Jim

[sparkle84]

SC mechanical brake light switch project

[andyt11]

the above article is probably the way I'm going to go but what draco said is interesting.

If I understand him correctly, I could buy two new factory switches and use them to activate a relay that would actually carry the current for the brake lights.

A normal relay as used for headlight application would be plenty adequate right?

[Por_sha911]

The link above is to modify your system. If you wish to just replace the two switches it is a relatively easy fix. Google Pelican replace brake light switches and you should find what you need.

[86 911 Targa]

Replace them.

Do a search, there was a very good post not too long ago on this same issue.

You will need an offset wrench for the back switch (closest to the dash).

Simple job.

Good luck,

Gerry

[carreraken]

Went thru the same problem with mine. Replaced the switches and problem solved.

[Jesse16]

Same as above for my 87. Simplest and least expensive fix is just replace the switches, easy job and you'll probably get many years of service. With new switches, the brake light comes on as it should, with light pressure. Of course there are plenty of "elegant" fixes if you chose to do a cool project.