Hi all
I'm upgrading my alternator on my 69 Cutlass to a CS130 as I need more amperage. I have found a 'resistor' in the wiring, anyone know whats this is for?

 

That is a diode. It's like a one way valve that allows current to flow in only one direction.

 

Thank you, any particular reason for it being on the gen lamp light wire?
I think its the gen lamp wire anyway, I havent explored it yet.

 

That's definitely a hack job, didn't come from the factory that way. That little diode is probably rated for only 1A. I'm not that familiar w/ the wire color codes so I can't tell what it is doing there, but I'd try to remove it if possible and clean up those splices. If you are upping the amperage of your alternator, you'll also need to beef up all wiring carrying the alternators output current (like the big red one bolted to the terminal on the back of the alternator). The factory harnesses were not designed for currents larger than what the factory offered in the alternator. Be careful and don't start a fire.

 

It is to prevent feedback to the ign system from the alternator. The car may continue to run after the key is turned off if it is not there. It is common when the alternator has been changed from a external regulator to an internal regulator. It is fine in the system in there now.

 

It’s not factory, but it’s needed for some aftermarket ignition systems. Without the diode the engine will continue to run with the key off. I would definitely repair the harness, the quality of wiring repair is pretty lousy.

 

Thanks Guys.
I will be tidying up the wiring, you should see some of the other cables, I got cables stuffed everywhere, some not connected to anything, I'll leave it in place albeit a tider job and I'm increasing the BAT cable gauge


Thanks once again
Aaron