I would Troubleshoot your elect.system with a mulit-meter. If you have a servie manual it only takes about 15 min. I also wouldn't rule out your R/R i bought a high dollar one that only lasted about 2 weeks before it took a dump and Cooked my battery. Your manual gives you all the specs for the wireing and componets. If something is out of tolerance It is your problem.

 

I forgot to mention that the R/R's for dynamos have 5 wires going into them: 3 from the dynamo (all yellow), 1 red (positive) and one green (ground) and the R/R's for alternators have 6 wires: the 5 from the other type of R/R and one that goes to the alternator (it's the wire through what the coil gets electro-magnetised) and this last one is usually orange.
Adapting an alternator R/R to a dynamo will not work or viceversa.