LED light

[Tyrone]

HI , I just read Glenn Abello's article on LED lighting for the BJ8. It mentions that the bulbs are polarity sensitive under the dash. When the article gets to the running lights and flashers it doesn't it doesn't mention polarity. Is it that these bulbs aren't polarity sensitive?
Thanks, Tyrone

 

[John Turney]

All LEDs are polarity sensitive.

 

[Bob_Spidell]

IIRC--too lazy to dig up my copy of the mag--the same article claims you cannot use an LED for the generator indicator light (something about it being part of a 'circuit'). However, I've done just that for several hundred miles with no problem. Anyone know the theory/story for sure?

 

[busybrit]

IIRC--too lazy to dig up my copy of the mag--the same article claims you cannot use an LED for the generator indicator light (something about it being part of a 'circuit'). However, I've done just that for several hundred miles with no problem. Anyone know the theory/story for sure?

The indicator light works when you supply power + to the bulb because the other side of the bulb is grounded at the non-running alternator/generator control box. It comes on when you turn your key.

When the grounded side of the bulb, "at the now running alternator/generator control box" is supplied a charge it becomes +, giving the bulb a + on both sides, bulb goes out. When the charging source fails the bulb is supplied a - ground by default, and comes on, hence the warning light.

LED bulbs will work, if your car is negative ground.

Hope this help.
-

 

[Keoke]

LED bulbs will work, if your car is negative ground.

 

[Bob_Spidell]

My car is positive ground and the generator light works the same with an LED as it did with an incandescent (for once, I'm thinking why the h**l is this working, instead of the other way around).

 

[Dave Richards]

I use LED dash lights in my BJ8. The car is positive ground. The generator LED light is on all the time, I'm simply going to switch that light back to incandescent.

 

[Bob_Spidell]

Why the heck does mine work???

 

[SaxMan]

I just did the LED upgrade on my '69 Sprite. Yes, I know the Sprite is a different bird than the "Big Healeys" as mine is a negative ground car. I have had no issues with using a LED for the generator light or the turn signal indicators (another suspect area). The only issue I've had is that the generator light is almost too bright and the blue LED glow comes out of the dash. The difference on the instrument faces though is literally night and day (pardon the pun)

Bob, I'm thinking yours may be working because somehow the light socket reversed its polarity...maybe in changing the bulb you grounded something that wasn't grounded with the incandescent bulb, or vice versa?

 

[CaptRandy]

They do have positive ground LED's.

 

[RAC68]

OK, so why install LEDs in the dash or any other part of the Healey? I have had the same incandescent bulbs in my dash, brake, and parking lights for at least the past 20 years so longevity isn't the motivation. I did install LEDs in the rear reflectors but that was a special situation. So, what is the big deal with LEDs?

Ray (64BJ8P1)

 

[Bob_Spidell]

... Bob, I'm thinking yours may be working because somehow the light socket reversed its polarity...maybe in changing the bulb you grounded something that wasn't grounded with the incandescent bulb, or vice versa?

Pretty sure I didn't do that. Besides, the 'D' in LED is for diode which, by definition, only passes current one way (though I do believe there are polarity insensitive LEDs that have some sort of internal circuitry--or even both polarities--so they will work with either grounding scheme).

At any rate, both incandescent bulbs and LEDs illuminate when current passes through them (for an LED, polarity matters). My understanding is this current is switched by the battery cutoff relay in the voltage regulator, so it seems either should work.

 

[Bob_Spidell]

OK, so why install LEDs in the dash or any other part of the Healey? I have had the same incandescent bulbs in my dash, brake, and parking lights for at least the past 20 years so longevity isn't the motivation. I did install LEDs in the rear reflectors but that was a special situation. So, what is the big deal with LEDs?

Ray (64BJ8P1)

The gauge displays are much brighter at night; my old eyes appreciate it (and you're probably saving 0.1A of current).

 

[RAC68]

Good point Bob. I guess I just don't drive my Healey as much at night anymore for it to make a big difference.

Ray(64BJ8P1)