On Saturday, June 13, 2015 at 5:08:42 PM UTC-4, Uncle Monster wrote:
On Saturday, June 13, 2015 at 10:13:40 AM UTC-5, trader_4 wrote:
On Saturday, June 13, 2015 at 10:53:38 AM UTC-4, Uncle Monster wrote:
On Saturday, June 13, 2015 at 7:08:04 AM UTC-5, Stormin Mormon wrote:
On 6/13/2015 12:30 AM, Uncle Monster wrote:
On Friday, June 12, 2015 at 10:11:05 PM UTC-5, bob haller wrote:

these OEM ONLY partss are why I bought a goodman furnace with AC..

the parts are common and affordable, generic,

I've sold a lot of Goodman systems but they aren't the only contractor grade systems that use generic parts. 8-)

[8~{} Uncle AC Monster


You may wish to tell us a couple of names?
-
As soon as I hit "post" I was sure someone was going to say tell us. I'm trying to remember and I just did. One was "Ducane", another "Armstrong" which are two of several brands under Allied Air Enterprises. There are some other private label brands that are the same on the inside. ^_^

http://www.ducanehvac.com/

http://www.armstrongair.com/

http://www.alliedair.com/

[8~{} Uncle AC Monster

I wouldn't be surprised if there are Rheem units that still use
a PSC fan, which can be multi-sourced too. And I wouldn't be
surprised if you bought a Goodman that uses an ECM motor, that
you have the same problem finding a generic replacement. Things
that were simple 20 years ago aren't so simple today.

So, update on status. I got the motor opened up. It does
have the easily identifiable thermistor, it's 1 ohm 20A.
Bad news is that it looks perfectly fine and also meters
out to 1 ohm. It's still possible that it's going partially
open when it gets hot, but I doubt it. The full motor current
is running through it and you'd think if it were partially
open, intermittent internally, it would generate heat, burn
up, be scorched, etc. That's what the pics of the failed ones
I saw online looked like.

Other bad news is that they put the electronics PC board
in the end cap, then poured 1/2" of silicone all over it,
covering up most of the components and making it impossible
to remove the board to see the backside, etc. The thermistor
sticks up above it, because it gets hot, so they left it
exposed. Theoretically, I think I could cut it off and if
lucky solder a new one onto it, but it would be tricky.
Could also put a 1 ohm
resistor in there temporarily as a test. But like I said,
given the fact that it looks perfect and measures out at 1 ohm,
I highly doubt it's the problem.

So, looks like I'm on the path to the $70 Ebay PSC motor.
Wonder if that counts as Rheem being able to use generic
parts?.....

Did you try powering the motor by itself to see if the same problem shows up without the heat from a running system? One of the most common problems I've come across with electronic equipment is cold solder joints. If you've decided you need to replace the motor, try peeling the silicone coating off the board so you can inspect the solder joints on the circuit board. A tiny crack can cause a thermal intermittent failure which can be repaired by soldering. If you can repair the board, you can pick up a tube of high temperature silicone rubber to recoat the board. 8-)

[8~{} Uncle Circuit Monster

I can't get to the board because they put the circuit board in the
end cap of the motor and then poured 1/2"+ silicone over the top of it.
It's completely covered by it and no way to get to the backside, or
even see most of the components. I agree that it would be great if it
were accessible, because it might be a bad solder joint or there
might be some common component that you could see that was burned up.
Or it could be the IC that must be there to control it, too.

I didn't try powering it after I removed it. There didn't seem to be
much point. I agree, it's probably thermal related. In the morning
when I tried it, it ran for about 15 mins before it went to slow speed.
I let it sit for about half an hour, tried it again, and it only went
for maybe 3 mins. I did measure that thermistor and it was 1 ohm.
I took a hair dryer to it and got it too hot to touch and the resistance
dropped to about .3 ohms, so looks like it's working.

So, I'm going to order a PSC motor and the cap. I managed to locate
a bracket for the cap too. Even that was a pain, because it was
hard to figure out which bracket fits which size cap. If I'm lucky
it should all be here Tues.

Thanks for the input.