Alternator Wiring With LED

[Dylan]

I'm helping a mate who has re wired his car. Including making his own dash cluster. He has gone with LED indicator lights for hi beam blinkers etc. AND the charge indicator light. I have wired alternators in the past but this isn't the norm.

I've done plenty of googling and found some way too hi tech answers or conflicting info.
I'd love some feedback from the guys on here. Plenty of varying knowledge and experience.

Just a suggestion of my thinking. Fit a X value resistor in place of a standard charge light and have a LED in parallel with that resistor in an orientation so that it illuminates when the alternator isn't charging.

Alternator is from a VT LS1.

Fire away all feedback appreciated.

[slewinson]

I would stick with a globe if possible as some regulators require the current as bias. Other way would be to use a resistor as suggested, with the value calculated based on the lamp wattage. Eg. 3 watt lamp would be 250mA current draw and a 47 or 56 ohm 5 watt resistor would draw similar current. It will get warm when lit too.

Simon.

[Gareth]

as slewinson suggested, the exciter circuit requires ballast (usually a 2-5watt globe, depending on the alternator), the trick we use for this is to fit a glass type fuse holder with a festoon globe inside, inline with the LED.

[Charlescrown]

I recently looked into this and yes the resistor will get warm but it will work. The biggest problem I had was finding a bulb holder for a 3 watt bulb. They all sell LED ones these days.

[Dylan]

Just for further thought. I've had an alternator running before with no charge light but with a diode between an ignition source and the alternator then the sensing wire to the battery. That worked on a VT V6 alternator.

[antus]

In my track car i have a bulb in parallel with a led. Led is visible, bulb is just in the loom out of sight.

[Dylan]

In my track car i have a bulb in parallel with a led. Led is visible, bulb is just in the loom out of sight.

When does the LED illuminate? Say with an ignition off-no charge scenario?

[Holden202T]

i've never had an issue with running a VR V6 alternator and an LED as the light .... ?!?!

does still stay on but very dull when engine is running .... but other than that works alright.

[Dylan]

That's interesting and when it's not charging it gets brighter?

[Holden202T]

yeah as in engine stopped ignition on.