Voltage Regulator

[Ben Mccree]

Engine now running and it sounds great trouble is I noticed some smoke coming from the coil on the voltage regulator.
It is a 1980 engine and what I did because the wiring to the alternator was within the loom, was to take the outer cover with the bushes in off the 1980 engine and slotted the original (1972) one on. Ran the engine for about five minutes and noticed the smoke and the coil was too hot to touch.
What I have done now is fit the original rotor inside the cover. No smoke this time, but the coil still gets hot. Alternator is charging.
I know it is not normal for something to smoke, but does the coil normally get hot? Any ideas why it smoked?
Ben

 

[pamcopete]

Ben.....,

Could be that the rotor that was installed when the smoke was coming from the regulator was shorted and drawing excessive current from the regulator. The coil does get hot, but that is subjective. Like, too hot to touch?

Squirt a little water on it and see if the water vaporizes, indicating that it is hotter than 100C, that would be too hot.

The important thing now is to verify that the regulator is regulating, so run it up to 3000 RPM and measure the battery voltage. Should be no more than 14.5 to 15.0 volts.

Measure the rotor resistance of the rotor that caused the smoke. Should be 5 Ohms.

Also keep in mind that if you are adjusting the regulator, the results will change when you put the cover back on, so you have to go through a very tiresome trial and error sequence to get it right.

Also, the mechanical regulators have a tendency to produce a high voltage at high RPM's, so you should do at least one run at 5,000 RPM for a few seconds to be sure that your battery voltage is not too high.

If it was me, I would just throw the regulator in the trash and source a suitable solid state regulator from a motor car application. Probably any three wire external regulator would work. You may have to alter the grounded brush to remove the ground and apply battery to it instead. If you use the '80 stator housing, the brushes are already isolated so it's just a matter of running battery to the inside brush, if necessary.

Plus, you'd be doing your mates a favor if you can tell them the part number of the regulator that you find.

This mod has been done here quite successfully using either a Chrysler regulator for $13 from the '70's or a AMC - Jeep regulator for about $25. I don't know if either of these brands are available over there" but if so I can provide you with the part numbers.

 

[Ben Mccree]

Cheers for that pamcopete, I'll have another dabble with it tomorrow and perhaps go for a ride. I'll report back. Ben