IR 78 280z alt wiring

[jalien]

Hello all,

 

So, I've searched and searched and searched for wiring diagrams of an IR alt. I am making my own wiring harness. I finally found a diagram and want to be sure of a few things...

1. There NEEDS to be a ground wire from alt to chassis? Just bolted in position is not enough?

2. The top spade of the T connection CAN be connected to the BATT post of alt?

3. Is the bottom spade of T connection an always on 12v when the ignition is in the ON position or is it momentary 12v when you are starting the engine?

4. Can I use ANY 12v indicator bulb between ignition and bottom spade of T connection?

 

Thank you!

[thisismatt]

Leg of T goes to an incandescent 12v charge indicator bulb whose other side is through ignition switched 12v. When the alt is "off" this leg is grounded at the alt, illuminating the charge indicator bulb. Once the alt is operating it outputs 12v to make the voltage potential across the bulb zero. If the alt starts to fail the voltage from the alt leg may drop and cause the bulb to glow at partial brightness.  I don't know if you can use aaaaany bulb...it probably shouldn't be an excessively high wattage bulb.

 

Top of T goes to a 12v source. Technically it should be able to be to a constant or a switched source.  If you loop it directly to the alt itself or the battery, it won't account very well for voltage drop elsewhere in the system. You may want to tap it off the ignition switch so that it can read through some wire resistance and tell the alt to increase output a bit.

 

I would have a dedicated ground wire off the alt to chassis personally. If not, make sure you have a ground from engine to chassis otherwise that high current will find another way, such as your speedometer cable as others have found out...