datzenmike Posted October 1, 2017 Report Share Posted October 1, 2017 The stock 521 comes with an externally mounted voltage regulator. A rounded metal box about the size of your fist. This what you mean? If not connected, it's possible that an internally regulated alternator has been used. For this to work two pairs of wires need to be connected together. Find the voltage regulator and see if it's plugged into the engine harness. If not are there wires jumpered together?? Does the alternator have a foil sticker on the rounded side? I believe if it says LT it's external regulated. If LR it's internal regulated. I do not think that is the original 521 alternator. After 45 or so years, chances are pretty good the alternator has been replaced. I think the original 521 alternator has a black plastic cover on the two small terminals that are in a "T" configuration. By removing that cover, you could remove the brush holder, and replace the alternator brushes easily. The original alternator was an external regulated alternator. More modern alternators use an internal regulator. On Datsuns, an external regulated alternator can be identified by a "F" and a "N" by the two small terminals. An internal regulated alternator can be identified by a "L" and a "S" mark by the two small terminals. This should answer that poorly worded first post. You'll have to look and see what you have and then get back. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.