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HVAC Guru
HVAC Guru, HVAC TECH
Category: HVAC
Satisfied Customers: 14389
Experience:  15yrs in the HVAC industry with certificates and degrees.
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Goodwin AC. Stopped working - Furnace Fan works. Read some

Customer Question

Goodwin AC. Stopped working - Furnace Fan works for circulation. Read some blogs and watched some videos, checked the capacitor and it bulged at the top so I replaced that. A few suggested I might as well change the Contactor if I am changing the capacitor. Changed both out - no problem. Now AC still not working and the furnace fan does not come on. AC and outside fan will work if I push in the button on the contactor.
Submitted: 1 year ago.
Category: HVAC
Expert:  HVAC Guru replied 1 year ago.

Hello, have you checked the 3 amp fuse on the control board in the furnace?

Customer: replied 1 year ago.
No. Any trick to checking it out?
Expert:  HVAC Guru replied 1 year ago.

Just get to the board pull the fuse off the board and check it, it may just be burned out causing the whole issue. It should be a slot fuse right on the board.

Customer: replied 1 year ago.
OK I will go check it out. Hang in there.
Expert:  HVAC Guru replied 1 year ago.

Yeah no problem

Customer: replied 1 year ago.
It looks good. It was on the bottom left corner of the board and it had the letter E on i. No burn, contact across top still looks fine.
Expert:  HVAC Guru replied 1 year ago.

Ok does the fan come on when selecting FAN ON at the thermostat?

Customer: replied 1 year ago.
No. But it did before I changed the capacitor and contactor.
Expert:  HVAC Guru replied 1 year ago.

Are any lights flashing on the board at all?

Customer: replied 1 year ago.
no lights
Expert:  HVAC Guru replied 1 year ago.

Ok can you check the power to the furnace or the out of the transformer it appears you lost your low voltage power to the board. Can you upload a picture of the wiring diagram here?

Customer: replied 1 year ago.
give me a few minutes.
Expert:  HVAC Guru replied 1 year ago.

ok

Customer: replied 1 year ago.
working on sending schematic pics now. The furnace is wired directly to the fuse box. Fuse is not tripped. what is best way to test for power?
Expert:  HVAC Guru replied 1 year ago.

You need a volt meter and check at the thermostat terminals, if you have a pic of the schematic on it I can tell you where to test.

Customer: replied 1 year ago.
Here are pics of the schematic - sorry there are 3, I had to get close ups.
Customer: replied 1 year ago.
I have a volt meter.
Expert:  HVAC Guru replied 1 year ago.

Ok you have a limit switch in line with the fuse on the transformer. Look around the unit for a resettable limit switch there should be one around the unit that is tripped

Customer: replied 1 year ago.
will it be on the board?
Expert:  HVAC Guru replied 1 year ago.

No it should be close by and have RED wires to it.

Customer: replied 1 year ago.
I cannot find it. Let's narrow it down. there are 3 sections when I have bother panels. Top section, furnace part - grates and ignitor, etc...
middle section - fan/blower
bottom section - A/C Panel.
Customer: replied 1 year ago.
I have 2 switches that look like the pic attached.
Expert:  HVAC Guru replied 1 year ago.

Yes push the button on the switches and see if it clicks int and you get a light on the control board.

Customer: replied 1 year ago.
That did not help. No lights on board. It seems strange that those switches are in the top section of the furnace on the underside of where the gas flues ignite for the furnace. The wires go down to the blower motor.
Expert:  HVAC Guru replied 1 year ago.

Can you follow the RED wire out of the fuse to the limit switch?

Customer: replied 1 year ago.
the fuse I checked earlier, I could actually pull off the board and put back on. So I should follow the leads from behind the board at the fuse?
Expert:  HVAC Guru replied 1 year ago.

If you see the large 9 pin molex plug on the board follow the red wire to that limit switch that should be the one...connect the wires to it together and see if the unit comes on.

Expert:  HVAC Guru replied 1 year ago.

Also confirm you have 120 volts to the furnace

Customer: replied 1 year ago.
in the jpeg attached is the switch the 2 red wires from the 9 pin molex go to. I disconnected them, pulled back the wire on the ends a bit and rub them together. No light on the board. I n3eed help in testing the 120 v to furnace. It is direct wired to the breaker box. Where is the best place to test?
Expert:  HVAC Guru replied 1 year ago.

Can you get to the junction box where the wiring goes to the unit? If so test across the black and white wires to it for 120 volts AC

Customer: replied 1 year ago.
120 volts, ac
Expert:  HVAC Guru replied 1 year ago.

Ok do you have the door switch depressed when testing this?

Expert:  HVAC Guru replied 1 year ago.

Hey I am going offline soon we can pick this up again tomorrow if you want,

Customer: replied 1 year ago.
I tested it after the on/off switch of the furnace and before the door switch. These boxes are side by side. One on the outside of the furnace, one on the inside.
Expert:  HVAC Guru replied 1 year ago.

You need the door panel switch in and check across pins 3 and 6 on that nine pin molex plug for 24 volts AC it should be the RED and Black wires there, look at the diagram and find the 3 and 6 pins on the diagram.

Expert:  HVAC Guru replied 1 year ago.

If you do not have 24 volts there you may have a bad transformer if you have bypassed that limit switch.

Customer: replied 1 year ago.
i am getting 24 volts there - I had extra hands and held the leads from the limit switch together while holding down the door switch and tested the 3 and 6 lines from the 9 pin molex. 28 volts.
Customer: replied 1 year ago.
Is the transformer the box that the 3 and 6 wires from the Molex go into?
Customer: replied 1 year ago.
I need to go to bed now - I can pick this up tomorrow afternoon. Is that possible?
Expert:  HVAC Guru replied 1 year ago.

OK just let me know if you still need help