Topic: GENERATOR IS HOT


FRITZ47    -- 11-25-2012 @ 8:44 PM
  I have a nice '47 Convertible and the car starts and runs perfectly, but on occasion stops running (no spark). I had Skip Haney rebuild the coil and thought I had it fixed, but the problem came back.

One thing that I noticed was that the generator is hot to the touch even if car is not running. There is a small spark when I connect the battery cable. I had a similar problem with a 1954 Buick and it turned out to be the voltage regulator. Any ideas.


supereal    -- 11-26-2012 @ 7:13 AM
  Quite often, that problem is due to a worn ignition switch, or bad connection at one of the terminals of the ignition resistor. Next time it happens, connect a jumper wire from the battery to the coil input. If the spark returns, place the jumper across the switch or the resistor to see if that allows the car to run. Intermittants are hard to find with a meter, as attaching the leads often causes the connection to close. Your generator heating is likely due to the failure of the cutout in the regulator to release. Substitute a known good regulator.


rotorwrench    -- 11-26-2012 @ 3:25 PM
  One of the three poles in the voltage regulator is a cut out. It's the one coresponding to the BAT terminal. If it is stuck closed, the generator will try to motor but the engine will act as the brake and the generator will get very hot. It will also run your battery down if you leave it connected. Sometimes you can successfully repair stuck points by getting them appart then cleaning and adjusting them for proper air gap. If they're too far gone then a new regulator is the hot smokin tip.


FRITZ47    -- 11-26-2012 @ 7:12 PM
  Thanks for the tips, which I will try. Nothing like an intermittent short to spoil your day.

Fritz


MICHV8    -- 11-27-2012 @ 9:17 AM
  A follow-up voltage regulator question...
On a 1939 Stock 6 volt system:
Battery drained down after a few days of driving short trips and died in a supermarket parking lot. So I had to jump it with a 12 volt for just a few seconds to get it running and then drove the car home which was about a 10-15 minute drive.
The fact that the car ran for 10-15 minutes seems to indicate that the generator was working (in other words, I was running for 10-15 minutes off the generator…correct?)
When I put an Ohm meter across the battery terminals, it showed only a static 5.9 volts even at high rpm, so does this indicate the problem is that the voltage regulator is not working?



TomO    -- 11-27-2012 @ 9:32 AM
  Michv8,

It could be either the generator or the regulator.

To test the generator, temporarily hook up a jumper from the Field to the Armature connections on the regulator with the engine throttle pulled out to about 1500 rpms while watching the voltmeter. The voltage should be above 7 volts. If you do not read above 7 volts, the generator is bad.

DO NOT leave that jumper on as it will burn out your generator.

Tom


37RAGTOPMAN    -- 11-30-2012 @ 4:05 PM
  FRITZ47
be sure to disconnect the battery, when not being used,
I never leave my battery connected when the left alone,
IF YOU HAVE A SHORT, this might cause a FIRE,,,!!!!
also it you disconnect the battery when running and it stays running, the generator should be charging,also if you disconnect the fan belt,and take a jumper 10gauge, from the battery to the arm terminal the generator should motor,[ spin,] becareful that nothing is in it way,
hope this helps 37RAGTOPMAN


supereal    -- 11-30-2012 @ 8:08 PM
  The quickest and easiest way to determine if the cutout in the regulator is at fault is to remove the wire to the BATT terminal at the regulator when the engine is off. If you get a spark when you touch the wire to the teminal, the cutout is stuck.


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