Originally Posted by stujamur
Dealer said he has never seen a bad regulator / rectifier so he very much doubhts that is the issue ( if it was cost is 160 ) .
He said to check current coming out of altenator .. Any tips / help / guidance in doing this ?
As the engine speeds up over 2200 RPM or so the voltage will decrease slightly as output flattens and the engine itself consumes more to run. The service manual has voltage and current curves for testing the system. Overall the voltage you listed is 0.5 to 1.0vdc lower than what I usually see on a TE610.
Probably the easiest way to see what is going on is to insert a proper size ammeter (or shunt with an accurate voltmeter) in series with the battery terminal and validate which direction the current is flowing (charge vs discharge) at various RPM. Careful with where you place it so the starter current does not blow the meter fuse (ie get a big enough ammeter or shunt device) or connect in line such that it avoids the starter.
While watching the ammeter or a voltmeter, which ever you can muster up, wait for the radiator fan to come on, turn on a turn signal, and apply the brakes to add more load and see what happens. You should have enough juice to charge the battery with this load easy. In fact you can still run an electric vest in the 65W to 90W range.
If that is not doable for you, try checking that each leg of the 3 phases going into the Voltage regulator has voltage on it (the 3 orange or yellow wires). Inspect the VR pins, look for loose connections, arcing (blackened nylon) and such. I found a new VR for $70 USD at my local dealer, Tasky's in Everett, WA a few years ago. In my case I was troubleshooting high voltage and speedo failures. Both VRs were the same and tend to run up to 15.1VDC at 2200RPM.
If a tie wrap is too close to the wires going to the VR connector it can pull the pin(s) sideways making a bad connection and leaving only 2 of the 3 phases providing power to the VR, thus slightly lower DC output.
Overall though, 13.7 to 14.2 is about right (if not lower than most TE610s) for a charged battery to run at. So I would not be too convinced something is wrong unless you can plug in a electric vest or such and see the voltage drop significantly.