3G alternator installed now horn and turns dont work

[dlinebar 2]

Hello

I installed a pick and pull 3g Alternator to replace my dead 1G. It works fine, charges good no issues there I think I wired it right, it was simple enough, but my turn signals and horn are not working now...I did nothing under the dash, just did the wireing and regulator removal under the hood. It could be they were not working before as I did not use them since last year I was wondering if anyone else had a similar issue and there was something I missed in the replacement or do I need to trouble shoot some other wiring gremlin not related to the alternator. Also when I turn on the lights the one rear break light stops working, works fine with lights off...anyone have something like this happen when they did the 3g upgrade?

[1969_Mach1 333]

The only thing I can think of right now is there is a ground wire for the headlight harness that attaches to the inner fender in the stock voltage regulator area.  I have a 3G alternator on my 69 Mach 1 and everything works fine.  I would think your issue is unrelated to the alternator.  To be sure, with the alternator disconnected do the problems stop?

[Midlife 814]

I agree that the most likely problem is a grounding point that you inadvertently altered.

[dlinebar 2]

Thanks I  will give that a look