Bad Alt Regulator?

[YadiStang]

I recently installed a newly purchased external alt regulator (Autolite Blue and Yellow) for my 1969 mustang base 302. I replaced an older regulator because I suspected it allowed my battery to overcharge...and boil over (acid under my hood...nice). The alt is a stock 65 amp.

I don't know if the new regulator is solid state or mechanical. Nonetheless, I think it has issues. When I start my car, and sometimes even when the car has been running, my lights flash up and down and the ammeter bounces. This happens for a few minutes and then will finally settle down. Sometimes it reoccurs randomly during a drive. So is this a potential symptom of a bad regulator?

 

[Noobz347]

@jrichker is a Fox guy but I have a feeling he might be familiar with this.

 

[Edbert]

Some surging/dimming of your lights during starter operation sounds normal to me. I do not know if the original regulator was mechanical on the '69s but they were on the '67s. Obviously no idea if your replacement is solid state or not either but the original mechanical style is easy to identify by looking at the backside. Mechanical ones had wire coils that would heat up at certain loads and flip open to break the circuit.

If your lights are doing that under normal driving it could be several things. Have you checked the alternator itself? Some alternators are internally regulated, I could see the alternator and the external regulator arguing with each other. Which lights are you seeing this on, headlights, dashboard or all of them? Again I've never dissected a '69 but my years also had regulators behind the gauge pods, I'd look at that if it is your dashboard that is exhibiting the problem and not the headlights. Another common part to fail after so many years is the headlight switch itself. The old designs were engineered so that the switch carried a full load too.

Sorry I cannot be of more help.

 

[YadiStang]

Good suggestions and I've thought about some of these. I don't think its the voltage regulator on the dash cluster since that is primarily for the gauges. Its the headlights and overall charging state that I'm looking seeing changing wildly. I've never seen an ammeter bounce like this normally. In fact the biggest complaint with the ford ammeter was that it barely moves and isn't a good visual indicator.

The ammeter and courtesy lights bounce with or without the headlights on so I'm not sure if my dimmer switch is the issue. Also, my dimmer switch does not carry the full load. I put in a relay harness when I changed to halogen bulbs.

Thinking about the possibility of a internal regulator on the alternator, I will have to look closer. My alternator looks like a stock alternator with several wires. I always thought single wire alternators had the internal regulator but I could be wrong.

I've checked all of my connections so I think I will try another brand regulator to see if that fixes it.

Also, its a new battery.

Here is a youtube video of the ammeter in action....
View: https://youtu.be/XmiRoPh7aQw