1954 Merc, stock - just installed a rebuilt generator, polarized it according to the Merc factoy repair manual and started it.  The amp gauge  shows a nice charge and a multi-meter voltage test at the battery shows 6.8 volts at about 1500 rpm.  Everything looked good  so I decided to test the voltage at the regulator next.  As I was beginning, I noticed that the regulator cover was quite warm (don't know if I ever noticed the temperature of a regulater cover before) so I checked the terminals with my finger.  The armature post was hot to the touch with the engine running for only 2-3 minutes.  I shut it down and looked in the troubleshooting section of the repair manual and in the Motors Manual to see if there were any references regarding hot regulators.  Finding nothing I am turning to the professional, old-timey fixit gurus; the smarter-than-I Y-Block forum guys!

The regulator has about 5,000 miles on it since installed new and it doesn't seem reasonable that it would naturally run hot .  What say you?

Heat is created when higher current than the wires and connections are rated for is passing through.
If your wires are good and the connections are clean and tight then it is possible the contact points inside the regulator are stuck on. This will cause the generator to put out max Amps.
Can the regulator be opened ? Some can be and you could check the points for pitting. Or if you have another one that is working to test.


1936 Ford 3W Coupe : 56 T-Bird 312, 47 Packard 3 speed, 40 juice brakes.
1968 Merc Cyclone FB GT 390, Getting a better front clip!
1977 Ford F-250 Supercab RWD Explorer Long box.
1976 Chev Camaro RS LT
Future rebuild : 1949 Ford F-1

Thanks Robs36, new wiring harness and all connections are good.  The cover is removable and I will look inside to see if any of the contacts are stuck or bad.  Probably failed as a result of the generator armature going south.   

If you are running a 6 volt system is your wiring harness a 6 volt  harness ?

I bet a local alternator rebuild shop can tell ya what you want to know.