Model a LED headlight problem

[Bella]

I installed LED headlights in my A. I have turn signals previously installed. The new LEDs flash off and or stay off completely when I use the signals. This does not happen with the old style bulbs. Any ideas?

[ModelA29]

LEDs have a trigger voltage - minimum voltage to light. When you turn on the turn signals the added draw could be dropping the available voltage below the minimum for the LED. Does it do it when the engine is revved up giving more current?
Filament bulbs will light even with low voltage - they just won't be as bright.

[Jim/GA]

Bad grounds in the headlights is a likely cause.

Are turn signals in the headlights?

[CT Jack]

Are your turn signals LED's or regular incandescent lamps? Is the flasher for the turn signals the type used for led's? If your flasher is the type used for incandescent lamps it could be causing a sizeable power draw thereby preventing the headlamps to illuminate.

[nkaminar]

Use the volt setting on you mutimeter to measure the voltage at the LED headlight bulbs when using the turn indicators and when not using them. You will need to remove the bulbs and measure the voltage at the pins in the socket. Use the ohm setting on the multimeter to check the ground connection from the ground pin in the socket to a good ground on the engine or better yet at the battery ground terminal.

[Bella]

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Thanks for the ideas. I’ll look into these. And get a multimeter. I’ll post what I find. Oh and the turn signals are not in the headlights. They are separate and incandescent.

[ModelA29]

Originally Posted by Bella

Thanks for the ideas. I’ll look into these. And get a multimeter. I’ll post what I find. Oh and the turn signals are not in the headlights. They are separate and incandescent.

If you find they work OK with the generator revved up and putting out enough power you may want to change your turn signal bulbs to LED and put in an LED flasher.

[katy]

Originally Posted by Bella

Thanks for the ideas. I’ll look into these. And get a multimeter. I’ll post what I find. Oh and the turn signals are not in the headlights. They are separate and incandescent.

Get an analogue meter, not digital.

[Keith True]

A good digital meter goes wonky on an A.Some say it is interference from the unshielded ignition,some say it is from the vibrating cutout,some say it is from the brushes passing over the bars on the generator,.Maybe it is a combination,or something completely different.Use LED bulbs for the tail,brake and turn,with an electronic flasher,and you should be fine.I found that if the voltage drops enough for the lights to drop off,they will recover and come back on.Then go off again,real fast.If they still do it with the engine revved up then you either have a ground problem,(likely) or the generator isn't putting out enough.(not really as likely)Thermal flashers really do draw quite a lot of juice.Put your hand on one in use,all that juice being used will heat that flasher pretty quick.

[nkaminar]

A small capacitor in parallel with the measuring leads on the digital multimeter will smooth out the readings.

[TomInCologne]

Funnily enough i never had a problem with my Digital Multimeter on the A, but maybe that's because i only use a good quality one, Benning MM 6-2. So cheap digital multimeters will cause problems, but so will cheap analog ones...