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Setting 3rd Brush
Posted: Thu Aug 08, 2019 6:56 pm
by FundyTides
On pursuing my problem with headlight bulbs failing as outlined in my earlier post, I have discovered that the nut holding the third brush plate is slightly loose, apparently allowing the brush to move, increasing the output to 10-12 amps. Can I just move the plate back to obtain a lower reading and tighten the nut or do I have to also loosen the 4 screws and move the brush holder assembly? The 4 screws are very difficult to get at because of the fact that my car is still equipped with the Vaporizer and the float bowl is quite close to the back of the generator.
Re: Setting 3rd Brush
Posted: Thu Aug 08, 2019 7:01 pm
by Scott_Conger
adjust back to a lower output and tighten nut gently. The insulation is likely very brittle and overzealousness here can lead to a ground path and give you "0" output.
Do NOT mess with the 4 screws in back.
Re: Setting 3rd Brush
Posted: Thu Aug 08, 2019 7:10 pm
by aDave
Re: Setting 3rd Brush
Posted: Thu Aug 08, 2019 7:11 pm
by aDave
Scott was faster...
As he said = easier.
Re: Setting 3rd Brush
Posted: Thu Aug 08, 2019 9:40 pm
by FundyTides
Thanks guys. That's what I was hoping for. I'll post how I make out.
Re: Setting 3rd Brush
Posted: Fri Aug 09, 2019 2:12 pm
by FundyTides
Regardless of how I adjusted the 3rd brush, output was still well in excess of 10 amp at road speed. Then suddenly, I think I discovered my problem. I have the notorious "smoke leak" in my wiring. I don't have a supply of smoke on hand to refill it so decided I had better find the problem. Pulled the dash panel and the wire from the ammeter to the ignition switch (yellow/black) was definitely hot. I disconnected wire going to generator cut-out and the problem went away. Appears to be a short in the cut-out. I'm pretty sure it is the diode type cutout that I installed more than a few years ago. Are these known to fail like this?
Re: Setting 3rd Brush
Posted: Fri Aug 09, 2019 3:51 pm
by aDave
Be EXTRA careful with what you are doing here..
Read this thread to see what happens when running the engine and cutout is disconnected (if I am understanding correctly what you are doing):
http://www.mtfca.com/discus/messages/17 ... 1307919845
Re: Setting 3rd Brush
Posted: Fri Aug 09, 2019 5:45 pm
by FundyTides
No, I didn't run the engine with the cutout disconnected. I know that can be disastrous. I could smell smoke so I turned the key off, removed the dash and turned the key back on. Wire from ignition switch to cut-out started to get hot. Shut key off and disconnected wire running to cutout. Turned key on and no smoke. Touched wire to cutout, big spark like a dead short so I think the battery was trying to "motor" the generator which makes me think that the cutout is faulty. Opinions?
Re: Setting 3rd Brush
Posted: Sat Aug 10, 2019 7:32 am
by FundyTides
Sorry, I made a mistake in my last post. The apparent short happens with the key off. The only way to stop it is to turn the battery disconnect switch off.
Re: Setting 3rd Brush
Posted: Tue Aug 27, 2019 5:56 pm
by FundyTides
Just an update for the benefit of those who would like to try to repair their own generator. After many conversations with Ron Patterson and some trial and error on my part, it turned out that the insulation on the brush plate had failed the last time I tried to tighten the third brush adjustment causing the generator to stop charging completely. Upon disassembly I also found that the lower insulator on the main terminal had broken apart and the lead from the field coil to the 3rd brush was bare. Following Ron's advice, I ordered a rebuilt brush plate and an insulting washer for the main terminal and fixed the bare wire with heat shrink insulation. I reinstalled the generator today and was able, again with Ron's advice, to set the brush plate and the 3rd brush properly. One word of caution, if you are taking a T generator apart, make note of which field wire is attached to which brush. In spite of the fact that most Ford instructions say to cross the wires from the field coils to the brushes, I found that mine were hooked up just the opposite. I reconnected them the same way and then bench tested with a battery and the generator "motored" in the proper direction (clockwise, viewed from the gear end) proving that this hookup was correct for this particular generator. Your results may vary. Thanks again to Ron for all his time and knowledge. I initially thought I would send the generator to Ron for rebuild but he graciously suggested that I could probably cure my issues without the expense of a complete rebuild. He was right and saved me considerable time and money. Great guy!!