Another voltage regulator thread 67 coupe

[robbz28]

I have had voltage regulator issues from the start, I bought a repop old school regulator and watched my needles jump for a couple of weeks before that one broke. I decided to get an electronic one (one of those off of ebay...modern voltage regulator) for 30 bucks. It came in the other day, I installed it and all of my gauges started working again...with no needle wiggle! I was excited. I thought I was going to finally be able to do away with those mechanical gauges hanging on my pillar. Anyway, I let my car sit there and warm up a bit and take it down the road, i see the water temp rising, the oil pressure varying with my revs...wonderful! Then all of a sudden the temp and pressure needles stop moving, but my fuel level is still working. It is still like that today....any ideas?? Just so you know I have new painless wiring and new sending units, if the regulator is at fault, then why does the fuel level still work?