Shoptalkforums.com

Hi Greg,

I'm a bit "slow" as an auto electrician, so have some trouble seeing the whole circuit with that 120ohm resistor connected from the + side of the coil to the Alt D+ connection, but I'd like to see you put an amp meter in series between the coil and the resistor to see if it's draining power with the ignition off. If it does it will not be a lot (1/10th amp?), but leave the car standing for a while and you might have a flat battery.

If there is no current drain with the power off, then it's a good solution - but then it might just be easier to leave the low-watt incandescent Alt light (for that two-way current the Alt circuit needs) in the dash and use LEDs for the other bulbs.

I have been running a diode between the positive on the coil and the alt. for well over 10 years and haven’t had a problem with it… yet. I don’t remember just what the size of the diode is as it is now covered with shrink wrap for protection from the sand and moisture. You have to remember that the diode is a gate and you have to have it setting in the proper direction.

To be honest, while it works and works well I don’t recommend it. If you break a belt or even throw your belt you have no way of knowing it until it is too late and you overheat the engine and there you go. Replacing the diode with an idiot light is something I have been slow to fix I guess but I sure would take adding the light back into consideration.

Lee

Hi Rob,

Just to provide some background on the car, it was originally totally rebuilt from the ground up in 2009 including the wiring and all of the warning lights were converted to LED.

I recently purchased the car and replaced the EFI engine with a new dual carby motor and needed to spend a lot of time tidying up all of the wiring and that's when I found out that there was an issue with the alternator light and the "non" charging of the battery.

I'll check to see if there is any current drain and get back to you.

Lee, I still have an LED light installed so I can see if I ever have a broken belt.

Regards
Greg

Hi Rob,

I just put the multimeter on the battery set to 10amps and it was showing a 0.005 draw. I then disconnected the load resistor and it was still showing 0.005. I am assuming that this is due to the alarm that I have installed in the car.

Regards
Greg

Hi Greg,

A good result then.

And Lee... he was using a resistor - not a diode. As you say a diode is a gate - one way electrical flow, but the worry was using a resistor that might allow a leakage flow in either direction.

Yep. Seems to be working fine. BTW, your website is great and I have used it on many occasions.

Regards
Greg

When I did the diode thing I went to an auto electric shop and they recommended the diode over a resistor. I am sure that either would work this was the course I was advised to travel.

At the time we were playing hide and seek out on the sand at night (not recommended now days). You had to run your CB to be notified if you were caught; if you ran the CV hot and came into camp late at night and forgot to turn it off before you had some barley pop then passed out everyone was kept awake by the truckers going by. To run the radio off the switch you idiot light gave you away hence the use of the diode. Switched CB and no idiot light and everyone got some Zee's.

Lee