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Triumph TR6 - Rear Brake Switch

Hey All,

My brake light switch at the pedal failed on me again. On opening the switch I notice a build up of crust on the contacts inside. I have cleaned these off and have brake lights again, but I was wondering what most people use to replace these? Do you stick with Lucas parts?

Ignatius Rigor

Hi Ignatius
the switch I installed was plastic and I have seen postings they do not last. I have not had a problem. Since you can/have opened yours, get the dielectric grease out. I do not understand why this is a problem for TR owners. There should not be any moisture down there. I do not even see rain on a shoe getting to the switch.
Rick C
Rick Crawford

I believe that an early BMW 1600-2 and 2002 brake switch will work and will most likely last longer.

The Buckeye site had something about this and I've hrad it from other TR owners around here. No personal experience though.

Good luck. W


I ended getting a Hella switch for BMW's from the guy I usually get my Triumph parts from locally (Part # 6DF 003 263-001)! He said they last longer that the stock part, but it cost twice as much $10. (Hopefully it last more than twice as long.)

Hi Ignatius

You might want to take that old switch to your GM dealer and see if they have something close. Then go to your scrap yard and find same probably free to a buck if you remove yourself. Not repops. I have never had one fail on the older stuff.

I get called to help wire a few rod projects and have never had a problem with an OE American brake switch. Even 40 years old original on a classic. Look like crap outside work perfect inside. I just test and wire them in.


Bill Brayford

Gentelmen - I am normally on the MG BBS, but jumped in here to get a link for a friend with a Triumph and saw the thread on brake light switches. Over the past couple of years there have been numerous threads on the various MG BBSs regarding the failure of brake light switches. It seems that almost everybody is having problems with replacement brake light switches. Several people have said that they have been told by the switch manufactures warn against using the hydraulic switches in systems with silicon fluid. While silicon fluid will seep past the tiniest hole in the diaphragms in the switches, if there is no hole (and I doubt that they all have holes in the diaphragms), no silicon can come into contact with the electrical elements of the switch to cause them to fail. I have had the pedal type switches in my MGB(which has no contact with the fluid at all) fail more often than the hydraulic switch in our TD so I feel that the silicon connection is just a red herring. The real problem, I have found by cutting the failed switches open is that the original switches have just died of old age (some older than others) and the replacement brake light switches sold today are extremely light duty and don't hold up to the 3 amps drawn by the brake lights for very long before the contacts burn again (I have had them burn in just two weeks). To correct the problem in my TD and MGB, I added a relay in the brake light circuit, along with a capacitor across the switch and a diode across the relay coil. Since doing that I have not had a single failure in over three years. I recently talked about this on the TD/TF mail list and was amazed at the amount of interest it generated (I was not aware of how common a problem this had become). One of the people that I sent the information to offered to put it in their web site so that it would be more accessible to others. If any of you out there in MG land is having a problem with failed brake light switches and are looking for a solution, click on Brake Light Relay . This link has the write up on what parts to get along with installation instructions and drawings for both negative ground and positive ground cars. It also has my address and price for a kit that includes the relay with a diode installed internally, capacitor and a relay socket for easier installation for those of you who wish to get the parts that way. Good luck - Dave
David DuBois

Looks like you got your problem solved, and yet another solution pops up! Triple C has a metal Lucas replacement at:

For those that might still be looking!

Rod Nichols

Sorry about that! Triple C's item is a reverse light switch. Must be the heat & smoke, 108 today & fires all around....

Rod Nichols

Hi Rod,

The Hella replacement is mostly metal, but with a plastic push thingey.

Ya, I know what you mean about the heat. I am glad I am close to the water so it doesn't get as hot.


This thread was discussed between 07/07/2003 and 24/07/2003

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