TEA 20 not charging?

[RonON]

Hello all. Hope that you are all safe and staying healthy! I have a 1952 TEA 20(85) still positive ground, 10 yr old generator, voltage regulator, fan/generator belt & wiring. Up until recently it ran well and the charging system worked well. Just started it up with the battery at 11.6 volts. Runs well but is not charging the battery. The belt has about 1/2-3/4 of an inch deflection when pushed down so it appears to be correct. When it is running, the voltage at the battery is still 11.6 volts rather than 13-14 volts. The red ignition light remains on regardless of rpm (when charging properly it turned off as it should have when revs were up above idle). Any quick tests to determine if the generator or voltage regulator are malfunctioning? Any other test/suggestions to determine the problem? Thanks in advance for any tips or help. Ron

 

[TR3driver]

Make sure it's a Lucas generator or equivalent. Lucas should be original for TE series, but I think TO series used Delco and they work differently. It's possible someone has switched parts around.

If it is Lucas, there's a good article here
https://www.anglo-agriparts.com/testing-dynamo-regulator

 

[RonON]

Thanks TR3driver. Some helpful tests here but am not sure which is most appropriate. I replaced the rear seal last year and therefore had to disconnect the electrical system. I"m not sure if that is when this started. Could the generator have lost it's polarization? Is it worthwhile polarizing the generator again and checking before doing any of the other tests? Any other tips or strategies (which test first?) to check? Ron

 

[John Deere D]

Quote:
I replaced the rear seal last year and therefore had to disconnect the electrical system. I'm not sure if that is when this started. Could the generator have lost it's polarization? Is it worthwhile polarizing the generator

Could the generator have lost it's polarization?..........YES...+ Earth / Ground original from factory.

Is it worthwhile polarizing the generator ...............YES......

Bob... Owner TEA-20 6 Volt all factory original...

 

[TR3driver]

Can't hurt to try repolarizing, but I've never seen one that was so thoroughly demagnetized that it wouldn't do at least something.

Start with the "Quick test". As noted, if that fails, try repolarizing. Also check that the voltage observed matches your battery polarity (ie D goes negative for positive ground). If the polarity is wrong, repolarize the generator.

If that looks OK, work through the steps in the detailed test, in the order given. The actions assume that all previous tests have passed. So if you find a problem, you should fix that and start over. It actually goes pretty quick, takes me longer to read and understand than to actually do the test.

These generators will deliver a lot more than their rated current, for a short time. It's up to the control box to limit the current output, otherwise the armature overheats, throws solder and dies. So it's not uncommon to find that one fault has caused another fault.