SIII Brake Light Switch

[warrenperkinson]

I have a SIIa with a SIII servo dual brake system.

The problem I have is that the brake light switch that screws into the top of the brake tower (part 575166) keeps failing. So far I have tried a Britpart x 2 and an original Land Rover part. All failed...

That's 3 failures in the last 3 months...

Has anyone had similar experiences? Have they been resolved, and if so how? Has anyone tried fitting a non-LR type brake light switch into the top of the tower? Any success? Could there be an electrical fault that is causing this (I've got 12v -ve earth)?

Any suggestions appreciated...

Cheers,
Warren.

[o2batsea]

Yup. I have had similar experiences with many replacement parts, particularly electric ones (melted a glow plug which burned up my wiring harness) so it's no surprise that you have gotten bad parts.
The switch is a pretty simple thing...a spring loaded plunger. If you still have one of them, try shooting some wd40 in there and work it a few times. Try it with a multimeter to be sure it's working.
IDK what the threads are, but maybe a diff lock switch from an LT230 will fit?

[I Leak Oil]

Sounds like an incredible string of bad luck to have that many fail in such a short time. Are you sure it's the switches that have failed? How do you know? It's pretty basic as far as switches go.

Perhaps you should eliminate the wiring, connectors, grounds and switch adjustment as possible culprits as well. Perhaps put a meter across the switch to see how many amps it's seeing.

[warrenperkinson]

I've checked the switch by pulling it out and activating it by hand (by pushing in the end). I know it's the switch because if I connect the two input wires the brake lights work perfectly. They draw 3.2 amps, which is 37 watts - that's reasonable, isn't it?

I've tried WD40 in the switch, with no success...

I've ordered a replacement.

Cheers...

[I Leak Oil]

3.2 amps sounds like it's in the right ball park. Next thing I'd do then is make sure the depth adjustment is reasonable when you install the new one. I guess if it's too deep you could be causing physical damage to the switch by over travelling.
There are all sorts of places to buy similar switches. If you want an alternative I'd start with McMaster-Carr. They have a great catalog that will give you all sorts of info on their stuff.

[wgnwheel]

I have had three fail - one inside someplace, and two where the spade-tabs are attached to the unit body (they broke free while pulling off the electrical wire/connectors for my regular LUCAS maintenance)... I ordered the replacements from England, along with several other sundries. When I wrote after the first occurrence, and asked the Parts Manager the same question about the 'non- original replacements failing', they sent out another immediately FOC. Then that one failed too. I wrote them back, and was told that similar experiences were being reported.

His truthful suggestion - Go original.

But the $$$ difference is big, and I can think of other parts I can buy for the offset - but logic tells me otherwise.

[wgnwheel]

Could the Original have been a lemon?