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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - LED flashers for positive ground

On the issue of LED compatible flashers for positive and negative ground:

There are many available for negative ground. www.superbrightleds.com sells a range.

The major question is what ones might work with positive ground? I wrote and asked one of the major manufacturers, and also wrote superbrightleds.com. The manufacturer never replied and superbrightleds.com said it did not carry any flashers for positive ground.

However, experimentation now suggests that a range of completely solid state flasher designed for LEDs will work with either negative OR positive ground.

I have tested two two-wire flashers (both for motorcycles) and both work perfectly with positive ground, giving a steady, quick flash.

Another three prong unit also works fine with positive ground, although the third tab which normally would run the pilot bulb (on the dash) does not appear to work.

While I can't guarantee results for every wiring configuration, I can say that the following units have worked on my positive ground 51 TD, and have now run for many hours without problems.
FL3-RED
LFS-1-PIN
LFS-1-FLAT
all available at http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fflashers.htm

I will be working on figuring out how to get the indicator lamp on the dash to work with these units over the next week (I believe that by running a lamp circuit in parallel with the load out leg of the flasher should work, but haven't done it yet).

For anyone considering DIY LED systems, I would recommend no-load flashers over load equalizers.

Load equalizers are designed to add load to the circuit enough to force a regular electro-mechanical flasher to trip. Because LEDs use so little power, they often will not trip the flasher themselves. The solution is either a LED-compatible flasher or adding load equalizers. By adding a load equalizer, you avoid the problem of flasher incompatibility. However...

The problem with load equalizers is that that they can generate significant heat, and must mount fairly close to the bulbs themselves. So in a small rubber boot housing a load equalizer and a led bulb, I can foresee heat buildup problems. This will not occur with a LED compatible flasher.

The superbrightleds.com website has this to say about load equalizers; "WARNING Load resistors heat up like a light bulb. Must be installed to make no contact with paint or plastic".

While it might be possible to wire a load equalizer into the underside of the fenders OUTSIDE the lamp housings, I would be very concerned about any attempt to install one inside the small rubber boots of the rear round or rectangular lamp housings, or inside the front running lamps.

Geoff Baker

This thread was discussed on 22/05/2010

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.