After putting most of my 1968 XR7 back together, today I noticed what I call a voltage tick or drop that happens every 5 seconds or so. Regardless if the car is running or not, both the amp gauge on the instrument cluster and my connecting charging system tester tick downward or pulse every few seconds. While running my headlights and interior lights dim/turn off and I can feel a small sputter of the engine during this tick. When I shut the engine off and take out the keys, the tick continues.
I’ve disconnected the battery and have done a load test with my tester and all signs on the battery point to it being okay, although I’m not ruling it out as it’s about 5 years old at this point.
I’m thinking maybe it’s the voltage regulator, but anyone have similar experiences or know where to look next?