installing an idiot alternator light ( led )... Pete in NH ?

[Nacho-RT74]

I have a question on this ( yes quite often I have doubts too on this topic LOL )

A friend of mine want to add an alternator idiot light ( being a Led ) to the Mopar system ( custom cluster ). AS FAR I KNOW all that I need is install a wire coming from the alt attached to one of the stator leads. This will give a ground signal when alt is "off" so the other led lead should be sourced with positive. Then when alt is spinning, the stator will keep sourcing, cuting the ground and sending signal, making the Cluster light off.

is that right ?

[tan top]

 sorry Nacho , have no idea  , but  thought about adding one my self  , 

[Pete in NH]

Nacho,

As far as I know Chrysler never used an "idiot light" on their alternator systems. GM and Ford did and as far as I know the light was operated by a lead from the voltage regulator. You want the light to come on when the alternator output voltage is lower than the battery voltage.

LED's need 1.25 volts to light but you also need to limit the current through them. Also, LED's don't like a reverse voltage across them. I think in your idea there is a good chance the LED would burn out from either too much current in one case or too much reverse voltage in another. But, you could try it LED's are very cheap!

American Motors used to use Motorola alternators and Motorola used a 4 diode system in the alternator. 3 diodes rectified the alternator winding voltage and one was a big isolation diode. They put the "idiot light" across that isolation diode which would only conduct if the alternator voltage was higher than the battery voltage. The disadvantage of that system was the isolation diode carried the full output current of the alternator and wasted quite a few watts of power.

[Nacho-RT74]

it's a led set already for automotive use, with a resistor. From a custom auto panel...







he had a Delco alt and I wired everything for it, but NOW HE WANT A MOPAR ALT!!! grrrr

[Nacho-RT74]

this is why I think it could work.

The mount on regulator system, SEEMS TO WORK with an stator lead as a trigger.

http://store.alternatorparts.com/partnod7018.aspx