Upgrade to 175amp alternator generator light on. How do I fix it?

[CBA]

Hi guys,

Just upgraded my alternator to a 175amp to as part of my Electric AC install and my generator light stays on. I've heard that I need a voltage regulator. My car is a '74 with an '83 3.2 SS motor w/ MSD ignition and the '83 wiring harness. From my understanding the '83 harness didn't have a separate wire to install a voltage regulator as it was part of the Jetronic system.

Does anyone know how to fix this problem? How to do it and what type of regulator I would need to install. Of course I could disconnect the light but I'd prefer to have it operational.

Thank you,

Joe

[John W.]

Joe, do some searches on the forum. As I recall you need to add a resistor to fix it. It’s explained here somewhere.

[CBA]

I'll try to search some more... I've searched a handful of times but didn't find anything, I'll trying searching resistor to see if I can dig it up. Thank you for the tip

[timmy2]

Service bulletin for going to a non remote VR alternator.

1982 911SC Alternator

[timmy2]

Part is NLA from Porsche, but I could make one up for you.
PM or email me.

Installed on a lamp holder:


What I have made for others:

[CBA]

Thank Dennis. This would be great. I sent you a PM.

[LM3929]

This is what an original one looks like


Lorne M.

[Jonny H]

To be clear, our 175A alternator has an internal voltage regulator. On cars that previously had an external regulator, the Porsche Service Bulletin procedure (posted by Dennis / timmy2) must be carried out. This is a wiring change but also may require the resistor mod posted above. We also reprint the bulletin in the back of our installation manual on our website.