RV6A Regulator

[jask]

My RV6A originally had a napa vr166 regulator. It was connected with the "I" terminal empty, "A" terminal connected to the "S" terminal then to the stator and the "F" terminal to the field of the alternator. The case is grounded to the firewall. The napa regulator lasted for several years and then began to fluxuate from 12 to 14.5 Volts about 3 times per second.

I have switched to several brands of the VR166 regulator and they are good to start but soon fluxuate followed by failure in about 2 to 3 hours. The regulator is located on the firewall, engine side. I added a heatsink to the latest regulator but it only lasted about 10 hours.

Has anyone experienced this problem and have a solution? Some regulators just have a field and battery connector. Can I connect one of those to my alternator field and stator? Has something happened to the alternator causing the problem?

 

[Mich48041]

It is possible that none of the regulators failed. Instead, a bad connection could
be the problem. Have you checked the alternator brushes? Some auto parts
stores will test alternators.

 

[lr172]

I don't believe that anything should be connected to the stator terminal on the alternator EXCEPT the S terminal on the VR. You can connect the S on the VR to the S on the alternator, but cannot bridge A & S and connect to the stator, as the A terminal is for bus voltage (i.e. sense + power source for VR circuitry). Most of us bridge A & S on the VR and connect it to the fused bus connection with nothing connected to the alt's Stator output. Maybe this is why your VR's keep going bad; The Stator output is not a stable power source for the VR and IS NOT intended to feed the A terminal on the VR.

I moved from the 166 to the Transpo VR. Nice quality and has a trim pot to set voltage level (be sure to put a dab of hot melt glue or something to keep it from moving in that high vibration area). Most of those 166 units are cheap off shore stuff. 800 hours and still running strong on my 6A. You can leave the S terminal open on the transpo VR; It works fine without it. You can also get the B&C regulator, as it has a built in OV protection. I built a separate OV board, so didn't need that feature.

Larry