I've been using a Duralast ND clone alternator on my plane, PN 14824. I chose it as a drop-in replacement when I did my engine swap (the old Motorola I had didn't have a mounting solution). Recently, I started experiencing alternator cutouts, where it would roll back to zero, then come back up, then out again, eventually deciding to stop. I replaced the alternator with a new one yesterday, same PN, and experienced the same problem. I'm now investigating the regulator.
The problem comes in with the fact that I have (on paper) an internally regulated alternator. I hadn't looked too closely at the system that the builder installed previously (I previously thought it was some sort of crowbar OVP setup), and today saw what appears to be an external voltage regulator mounted on the firewall that the field wire goes to. It's a four post regulator with the field input, nothing on the stator pin, and I and A terminals going up into the cabin; the A wire goes through an unmarked box which I assume is either an OVP relay or maybe a noise filter of some sort. I still need to finish tracing the wires behind the panel, but at some point they run to the alternator controls which consist of a switch and a 5 amp breaker.
Have I inadvertently been running piggybacked voltage regulators this whole time? Should I bypass the firewall mounted regulator, and if so how would it be wired? Or should I fire the parts cannon at that regulator (I see a few Duralast part numbers that may work, but I'm not sure which) and go on my way?
The problem comes in with the fact that I have (on paper) an internally regulated alternator. I hadn't looked too closely at the system that the builder installed previously (I previously thought it was some sort of crowbar OVP setup), and today saw what appears to be an external voltage regulator mounted on the firewall that the field wire goes to. It's a four post regulator with the field input, nothing on the stator pin, and I and A terminals going up into the cabin; the A wire goes through an unmarked box which I assume is either an OVP relay or maybe a noise filter of some sort. I still need to finish tracing the wires behind the panel, but at some point they run to the alternator controls which consist of a switch and a 5 amp breaker.
Have I inadvertently been running piggybacked voltage regulators this whole time? Should I bypass the firewall mounted regulator, and if so how would it be wired? Or should I fire the parts cannon at that regulator (I see a few Duralast part numbers that may work, but I'm not sure which) and go on my way?
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