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Turn Signal Electrical Question

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glemon

glemon

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My turn signal indicator light on my TR250 was very dim, I recently replaced it with an LED light, which seems to be much brighter, but....it only works if I indicate a right turn, are LED lights "handed"? could I have gotten a right hand only one.....just kidding. I am no electrical genius, but not that bad.

I suspect the voltage is lower n the left turn signal circuit (it has always blinked slower than the right one) I have checked all the connections and they seem good. I have a multi-meter and know just enough about how to use it to be dangerous, is there a way to try to track down the source of the voltage drop?
 
glemon said:
are LED lights "handed"?
Click to expand...
Bingo !

Seriously, LED stands for light emitting DIODE, meaning they only work for one polarity. The TR250 turn signal indicator relies on the fact that incandescent bulbs don't care about polarity.

Talk to your LED vendor, they may have a unit that provides for operation with either polarity. Otherwise, you'll have to rearrange the turn indicator circuit to use a (or two) LED.
 

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yep been there tried it on my TR6 only lit in in one direction

cant remember if it was left or right turn only

Hondo
 
I also tried that on our Spitfire. I went back to an incandescent bulb.
 
I have been out in the garage messing with this for a couple of hours, I was beginning to wonder the same thing you told me Randall, my post was joking about the handedness but yeah kind of like that.

In Futzing around with my connections though I got the right at left indicators to blink at the same rate by cleaning and tightening various connections.

The LED sure makes a nice bright light, if I wired it up with both green/white and green/red going to power one side (middle contact on the bulb and bulb holder), and grounded the other side would that work, our would that mess up my turn signal circuit? Like both sides would light at once or all the smoke would come out?
 
glemon said:
if I wired it up with both green/white and green/red going to power one side (middle contact on the bulb and bulb holder),
Click to expand...
No smoke, just both sides light up at once.

Some possibly workable alternatives:

1) Use a 3-terminal flasher, connect the dash lamp to the 3rd terminal. That's how the TR2-4A are wired.

2) Use two LEDs (possibly even in the same housing), so you can wire one to each side.

3) Insert a diode bridge between the LED and the original turn wiring https://www.jameco.com/webapp/wcs/stores/...WSF&CID=GMC

4) Add a relay with its coil wired in place of the original turn signal indicator bulb, and the contacts switching the LED.

5) Use two diodes (rather than the bridge), and wire the other side of the LED to ground.

Or of course just keep using an incandescent.
 
As of now I have gone back to incandescent, I have ordered some 8w bulbs from LBcarco for the big guages and the turn signal indicator.

When I was going down to Kansas City a couple weeks ago for the All British show the guy going with me said I had my flasher on about 20 miles. When I see others do this I think they are inattentive drivers, I don't like noisy blinkers (I think there are some options to put a buzzer in the circuit) hence my current mission to get a turn signal indicator I can see flashing in the sunlight.

This is my third LED order, first were wrong size (my fault) next order was not as described on the website (their fault) then the ones I was messing with today and figured out the polarity thing with the help of the forum, tired of messing around with the leds, I wouldn't have the first idea of how to wire up a diode bridge, I could probably covert to the three wire flasher, but would prefer the wiring remain stock, so when I look at the book the car should match.

Thanks for your help I'll report on the 8w tungsten bulbs when I get them.
 
glemon said:
I wouldn't have the first idea of how to wire up a diode bridge,
Click to expand...
Shouldn't be hard at all. The bridge has 4 leads, marked ~, +, -. The two ~ leads go to the original wires. The + and - go to the LED anode & cathode (+ and -) respectively.
 
Hello, I just started having a problem where my left turn signal flashes correctly, but not the right turn signal. The have to manually work right turn signal in order to get the blub to flash. Why would one flash properly and not the other?

Thanks, Alex

P.S. Didn't mean to hijack the thread.
 
First thing to check would be all the bulbs on the right side. The flasher is sensitive to the amount of current drawn, so anything that reduces (or increases) the current could cause it not to flash.
 
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