York Diamond 90 Blower Motor not running - http://www.hvacmechanic.com/ Forums

Original message

kylek

99.250.105.58

"York Diamond 90 Blower Motor not running" , posted Wed 16 Jul 20:32

Uses White-Rodgers control board.
Blower won't run either when the thermostat is set to Fan On, or when it's set to Fan Auto & Cool. Just stopped working all of a sudden (was running all night no problem).
Turned off power - when power reapplied, slight hum heard, and red light on control board blinks once.
Checked for burnt wires but didn't find any.

Any ideas what could be wrong?

Kyle K.

Replies:

Houston204

98.196.66.53

"Re(1):York Diamond 90 Blower Motor not runnin" , posted Thu 17 Jul 00:15

If the blower wheel spins freely with power removed, it is probably only a capacitor.

Usually strapped to the blower.

You can test it yourself for $30. Remove power and allow a few minutes for your cap to bleed down before handling it.

"Tip of the Day" Remember to remove power first.

kylek

99.250.105.58

"Re(2):York Diamond 90 Blower Motor not runnin" , posted Thu 17 Jul 10:01

Thanks Houston204.
How do I properly test the capacitor with a multimeter?
I tried the ohmmeter test, but it didn't work.
I went & bought a new capacitor for $20, but it's not an exact replacement.
Old one = GE 97F9001 370VAC 7.5uf +6% -6%
New one = Rotom Dual 370/440V 7.5MFD +5%-5%

Needless to say, the furnace fan still doesn't run with the new capacitor.
And still getting the single red light flash with the new capacitor.

Kyle K.

Houston204

98.196.66.53

"Re(3):York Diamond 90 Blower Motor not runnin" , posted Thu 17 Jul 21:29:

Your new cap is exact enough. Measure for 120 volts at cool and neutral to your motor with demand. (Usually black and white)

I've seen the old tech's use the ohm test for caps when I first started in this field. I have always Fieldpiece meters which can actually measure capacitors (not just broken, or maybe okay). I bought the one pictured above because I needed a new non-contact volt stick and this came with both for $25 on sale. It works okay and can measure caps.

I usually use this one.

"Tip of the Day" Remember to remove power first.

[this message was edited by Houston204 on Thu 17 Jul 21:31]