Charging Problem - generator

I'm not a mechanic and my electrical system knowledge is limited....with that here is the issue:

My generator ceased solid and smoked the belt off. I was on a long trip and met and awesome crop duster, A&P and fellow cub owner in ND. He gave me a used gen, I got a belt from napa and he put it on. Its still not charging however. He put power to the gen in reverse before install and it turned. He also flashed the field. I ended up just charging the batt and flying home to Canada (didn't have far and fighting weather the whole trip). Now that home changed the regulator and same problem. I don't see any bad fuses and the gen circuit breaker never popped but I tried pulling/resetting anyway.

Does anyone have ideas on what the issue might be? Is the used gen most likely no good? I'm guessing most people will say just do the alternator conversion now but was hoping to hold off on that until next annual inspection.

Thanks in advance

He 'flashed the field' is a red flag for me. Usually done without cause and usually done incorrectly. Take the generator to an auto parts store that can test it (tell them it's off an old truck). If it tests good then you'll need to check the reg.

In all seriousness, if either the generator or the reg is bad, it's time for the alternator. You'll be happy when it's installed.

Web

Flashing a gen field...that's 58 yrs ago tech from auto mech school. Lots of links online on how and how not to do it....and not cook the reg.

Gary

BC12D-4-85 said:

Flashing a gen field...that's 58 yrs ago tech from auto mech school. Lots of links online on how and how not to do it....and not cook the reg.

Gary

Click to expand...

And . . . .

Web

This is a good, concise description of how it's done. But I stand by my observation that 'flashing the field' is rarely required and has done more harm over the years than good. The ONLY reasons to flash the field on a generator is if it has been stored so long that the poles have lost their magnetism or if some dinglefritz has polarized them backwards.

Please proceed carefully.

Web

I recall a couple of different methods depending on generator field design and magnetic polarity desired. Ford vs others for example. Your suggestion above is a good one.

It's been a few yrs as noted but reviewing the auto tech stuff polarization varied by manufacturer and negative or positive ground on older vehicles. We did it at overhaul or whenever the charging components were replaced.

Gary

https://www.shortwingpipers.org/forum/showthread.php?6050-Charging-Troubles

https://www.shortwingpipers.org/forum/showthread.php?10491-Generator-not-charging

The gen def had been sitting on the shelf several years...he had several cubs he converted to alt

I'll be the odd man out & say keep the generator, and just figure out what's wrong with it.
An alternator conversion kit will probably set you back close to $1K,
and depending on your flying habits may not really be an improvement.
I've still got the stock 35A generator on my 53 180 and am perfectly happy with it.
And I've got a spare one sitting on the shelf, donated by a friend who upgraded to an alternator "because they're better".
(even though his generator system was working perfectly)

If you have a local automotive electrical shop, take the generator & regulator there for troubleshooting.
It's probably something that can be fixed pretty cheaply.
And IMHO the expression "flashing the field" is misleading and can lead to the procedure being done wrong.
You are momentarily connecting a jumper between the battery terminal and the armature terminal--
just a touch resulting in a big fat spark is enough.
It was easy to remember how to do it on the Bosch regulator on my old Harley-- "B+ to D+".
I don't know if jumpering to the field terminal will cause damage, but it probably won't do it any good.