Dayton 4lm38b with generac rotor/stator no power output

Generac, Guardian, Honeywell, Siemens, Centurion, Watchdog, Bryant, Olympian & Carrier Liquid Cooled Home Standby & Commercial generator troubleshooting and repair questions
mjr46
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Chris wrote:
Thu Jan 30, 2020 7:24 am
This could be two things actually. If the AVR isn't getting DPE power from the 2&6 wires when the alternator is making voltage, that would explain it. You should double check that when 12V is applied, you have AC voltage on the 2&6 wires (wire numbers not positions on the AVR) You could also have a bad AVR. In either case, I think it's also going to need a field boost kit...

Voltage Regulator: https://shop.gentekpower.com/products/g ... ulator-avr
Field Boost Kit: https://shop.gentekpower.com/products/g ... -upfit-kit
so where are 2 and 6 going to be on the regulator? and do i disconnect the 2 and 6 wire to test while applying voltage on the #4? and what should the spec be i'm looking for? also is it hard/how is the field boost kit installed? once i pin this last test down and you get back with me i'll have my mom order theses parts from you that you listed. thanks for all the help chris!!!
Chris
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The 2 and 6 wires will be the last 2 wires on the AVR. They may also be listed as 2 and 162 or something to that effect. They should also pass through the DPE breaker, which should be checked for continuity.

With those 2 wires REMOVED from the AVR, one lead in each wire and the meter set to AC voltage, you should see somewhere in the 70-120V range, but anything around there is fine. That winding in the stator is power for the AVR which then gets converted to DC by the AVR to power the rotor output on the 0 and 4 wires.

If we're NOT making power on those 2 wires, that's not good. Some stators have a DPE bypass wire which will be capped off and loose coming from the stator's harness which can be used in a pinch (this would be a pinch) since there is an internal and non-resettable thermal overload. We'll talk about that if the time comes...

For now, lets just see if you're making voltage on those 2 wires and that will lead us in the right direction.

You're absolutely welcome!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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mjr46
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Chris wrote:
Thu Jan 30, 2020 5:42 pm
The 2 and 6 wires will be the last 2 wires on the AVR. They may also be listed as 2 and 162 or something to that effect. They should also pass through the DPE breaker, which should be checked for continuity.

With those 2 wires REMOVED from the AVR, one lead in each wire and the meter set to AC voltage, you should see somewhere in the 70-120V range, but anything around there is fine. That winding in the stator is power for the AVR which then gets converted to DC by the AVR to power the rotor output on the 0 and 4 wires.

If we're NOT making power on those 2 wires, that's not good. Some stators have a DPE bypass wire which will be capped off and loose coming from the stator's harness which can be used in a pinch (this would be a pinch) since there is an internal and non-resettable thermal overload. We'll talk about that if the time comes...

For now, lets just see if you're making voltage on those 2 wires and that will lead us in the right direction.

You're absolutely welcome!
okay so with the 4 wire still on the avr i clipped on a 12v lead from the battery and 2 and 6 wire disconnected and leads going from my dvom to each respective lead 2/6 i get 153-154 volts.....so looks like it is making voltage ....although outside the spec you listed.......so where to from here?
Chris
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That's a very good sign! I think that basically eliminated everything else (if I'm remembering correctly) and that would lead me back to my AVR and field boost kit assumption. We've proved that we have output, good field resistance now, and DPE voltage to the AVR, but yet still no life. We also determined that the field boost is weak or not working, however a bad AVR can cause those symptoms as well. It might be worth (if you don't mind an extended downtime) ordering just the AVR and seeing if that solves the issues without the field boost kit. If it does, great! If not, you can then test the system just by bumping 12V quickly to the #4 wire and the new AVR should take over and produce normal voltage. If so, we know you need the field boost kit then.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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mjr46
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Chris wrote:
Thu Jan 30, 2020 8:31 pm
That's a very good sign! I think that basically eliminated everything else (if I'm remembering correctly) and that would lead me back to my AVR and field boost kit assumption. We've proved that we have output, good field resistance now, and DPE voltage to the AVR, but yet still no life. We also determined that the field boost is weak or not working, however a bad AVR can cause those symptoms as well. It might be worth (if you don't mind an extended downtime) ordering just the AVR and seeing if that solves the issues without the field boost kit. If it does, great! If not, you can then test the system just by bumping 12V quickly to the #4 wire and the new AVR should take over and produce normal voltage. If so, we know you need the field boost kit then.
okay...sounds like a plan.....can we order that through you? i'll see if my mom wants to order both or just the one......we may do both because i want this done and over with ...it has been a thorn in my side every time the power has gone out for her the last 2 years which i think has only been a few times.
Chris
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Yes absolutely, it's how I keep this site running!

The AVR can be seen here: https://shop.gentekpower.com/products/g ... ulator-avr
The field boost kit here: https://shop.gentekpower.com/products/g ... -upfit-kit

The voltage regulator you have may not have the cooling fins that the one above does. I always recommend that version above and to just extend the 2 screws with longer ones by about 3/8". Better and more cost effective regulator than the flat one, which is still available. 83048 is the part number of the flat voltage regulator and 83049 got replaced by the 0F9719 version above.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
mjr46
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Chris wrote:
Fri Jan 31, 2020 10:02 am
Yes absolutely, it's how I keep this site running!

The AVR can be seen here: https://shop.gentekpower.com/products/g ... ulator-avr
The field boost kit here: https://shop.gentekpower.com/products/g ... -upfit-kit

The voltage regulator you have may not have the cooling fins that the one above does. I always recommend that version above and to just extend the 2 screws with longer ones by about 3/8". Better and more cost effective regulator than the flat one, which is still available. 83048 is the part number of the flat voltage regulator and 83049 got replaced by the 0F9719 version above.
yeah, i had already read about extending the screws for the updated regulator.........i talked to her last night, we're gonna order both through you either tonight or tomorrow when i get a chance to get back over to her house. that way if we need the boost kit we'll have it!! i'll let you know when she has placed her order! thanks again!!!
Birken Vogt
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All the ones I have worked on had the screws already long enough for the fins almost like they intended it to work this way. And I've done quite a lot.

Question here: has the flat one ever been updated to the new layout/components of the finned one, or is it the same old version? Or maybe they are still working through old stock?
Chris
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I haven't ordered one in a long time, but when I did, they still had the old white phillips head pot on them long after the re-design of the 0F9719 regs to the new style brass flat head pot.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
mjr46
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Chris wrote:
Fri Jan 31, 2020 3:31 pm
I haven't ordered one in a long time, but when I did, they still had the old white phillips head pot on them long after the re-design of the 0F9719 regs to the new style brass flat head pot.
so my mom should of ordered the stuff from you last night , she was making an account when i left and had the page up.......so i'll let you know how all goes when parts arrive....thanks again Chris!!!
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