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MG TD TF 1500 - Neg grnd LED headlight in T-Series?

Positive ground LED headlamp bulbs are scarce as hen's teeth

It seems to me, that installing the much more common negative ground LED headlight bulb in a positive ground T-Series, could be done by simply reversing the wires.

Am I off-base on this?

Gord Clark
Rockburn, Qué.
Gord Clark

I think safely and reliably isolating the reversed wiring from the car's frame metal could be a problem. The led bulbs I got from LBC are polarity neutral and work fine in my pos. ground TD.

Jud
J K Chapin

Gord, all the early LED bulbs were polarity sensitive, so no switching of wires.
As Jud points out apparently there are polarity neutral bulbs now.. I was not aware of that. I am always learning. on the polarity neutral bulbs, switch away.
Regards, Tom
tm peterson

Jud,

My thinking is to reverse only the wires at the light socket. The only issue I can think of , is power to the light in out T-Series cars, is pure DC, whereas power from an alternator, is half-wave AC.

I do have a pair of LBC headlamps and indeed, they are a vast improvement.

I'm only looking for some flexibility in selecting additional LED lamps as there seem to be so many from which to choose, but I assume, that all are negative grnd.

Gord Clark
Rockburn, Qué.
Gord Clark

I am not sure how you would reverse the wires since you are dealing with two hots (one dim and one for brights) and only one ground wire. I suppose you could do the job provided you install some diodes on each incoming hot wire to the head light ground to prevent a backfeed to each headlight beam. To be honest I do not drive the TF much at night so I have never bothered beyond some good halogen sealed beams. On my TR8 however I installed some high dollar Holley retro bright led head lights and I would say they are worth the money compared to the many I looked at for months before I finally plunked down the cash for them.
L E D LaVerne

... never thought of that, LaVerne.

Back to squared one!

Gord
Gord Clark

Why not switch the batt cables and change the polarity of the gen/regulator?
(you may want to switch the ammeter leads, or it will read backwards)

see:https://autorestorer.com/articles/system_polarity_and_polarizing_generators-1874
J Stone

The power to the bulbs is never AC. Whatever the generator puts out is smoothed to DC by the battery (except possibly some high frequency spikes) before it reaches the lights. So no worry on that end.
Cheap LEDs are not overvoltage protected. The Lucas Regulator may produce peak voltages that damage unprotected LEDs. Damage results in loss of brightness or change in color. This can be prevented by a transil in parallel or 1-2 Diodes in series.
I have made good experiences with AUXITO Headlight bulbs, both H7 and H4 (the latter is relevant for the TD). Good light distribution, high brightness and no defects so far. Not cheap, but still reasonable. I don‘t know if the H4 are polarity sensitive, though, since I have neg. ground. Some of their H7 bulbs ARE sensitive to polarity.
Rgds Mike
Mike Fritsch

You would probably be safe if you actually ran a new positive and negative wire from the battery. Unhook the lighting circuit at the regulator and tie in there. If I were to do it that way, I would install a new fuse box and fuse the headlights.

Just like the two power terminals in the dash, you would need to fully isolate the circuit.
Bruce Cunha

I have been planning for some while, to switch polarity.

I'm now convinced to do it. Fooling around with lash- ups ain't gonna get me very far!

Thanks all.

Gord Clark
Rockburn, Qué.
Gord Clark

Mike Fritsch

Can you send me the part number of the H4 Led you installed?

Jud:

Can you share the part number of the positive ground LED bulbs you purchased from LBC?
Michael Balahutrak

Michael, take a look at the latest LBCarCo newsletter at
LBCarCoNews<lbcarconews@newsletter.lbcarco.com>

Jeff's writeup shows things pretty well. Bud
Bud Krueger

Michael, these are what I installed:
https://www.lbcarco.com/cgi-bin/or17?runprog=lbcnews&page=/sft.html&o=

They are the same as what Bud is referencing.

Jud
J K Chapin

Jud,

i bought a pair of LBCCarCo's "BiPolar" LED headlamps (grnd in sensitive). Will check tomorrow.

Gord Clark
Rockburn, Qué.
Gord Clark

Gord, if you are looking to LED options for other lights on your LBC, other than headlights, take a look at www.brittrix.com

Most sets are polarity neutral.
Lew Palmer

Yes so did I
They are on sale now at LBC - Installed them yesterday and they work, fit and look great

Check out Ledlight.com for instrument lights - I got the green ones and fit is perfectly tighttt! Be careful to order only 69798 for positive ground TD E10 base SKU69798G is green - fantastic look

Also ordered turn-signal / parking front bulb with parallel pin base 30SMD BA15D Sku 64972W - they did not carry the yellows

se are me mounting mods

This should alleviate the stress on the generator




Michael Balahutrak

Jud, it appears your link takes you to shirts on the LBC site
Regards, Tom
tm peterson

Tom, I think this will do it but LBC changes its webpage frequently. Jud
https://www.lbcarco.com/cgi-bin/or17?runprog=lbcnews&page=/sft.html&o=
J K Chapin

Jud, It still takes me to shirts. I will poke around a bit

Regards, Tom
tm peterson

On the Shirts page click on Specials up at the top. One of the specials listed is the LED headlights.

Jud
J K Chapin

This thread was discussed between 24/09/2024 and 12/12/2024

MG TD TF 1500 index

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