The D+ excitor circuit is okay at 14.1, but the B+ charging circuit at 13.2V is much too low and should be the same or slightly higher than D+. One of the internal diodes is possibly faulty (in the Bosch design likely one of the 3 output diodes, see diagram below). The voltage drop to battery is fine. The voltage regulator is likely okay. On the test bench you want to see closer to 14.5V on B+, but in practice when installed the Volvo spec is more like 13.75-14.35V depending on residual loads and battery charge/condition. Unless you've got a high end DVM, they can add to inaccuracy, so 14V at D+ is okay. BTW, 14V stamped on the regulator is just a nominal voltage. Also, the Bosch factory set spec for our regulators was originally 14.5V, but some replacements may be 14.4, while other brands can be anywhere from 14.1/14.2 to 14.8V, so people insisting on always seeing 14.5V may be incorrect.

Before condemning the rebuild there are a few things you should do. Remake the B+ terminal and ground post terminal connections polishing up the cable spades. When you retest, do so up around 2000 rpm or slightly higher (I believe min 1750 rpm is the actual Volvo spec) and with all loads off, esp. headlights, fan, wipers and defrost. For the type of DRL switch you have, you can use the middle park light position for quick tests, but for proper measurements you need to either pull the fuses or disconnect the headlamps.

The FAQ here has lots more on charging system issues, including specific tests for faulty diodes
https://www.brickboard.com/FAQ/700-900/ElectricalStarting.htm#CheckingAlternatorDiodes


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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now