rain came and AC or thrermostat stopped working

[djw]

We have recently been drenched with rain, but no lightning. I turned down the AC a little because of the humidity but noticed it did not come on. I turned the fan to the on position and it did not come on. I tripped the indoor circuit breaker to the AC (actually it is a Goodman gas pack- 6 yrs old) but still no fan or AC. Could the rain have caused a problem? I looked and there wasn't any flooding around the unit.

[HayZee518]

Is there a sensing bulb thermostat outside? I seen installations where there was a thermostat bulb outside, so when the temperature dropped to a preset level, the ac or heat didn't turn on at all no matter where the inside thermostat was set. if you have an analog meter start at the source and check voltages along its path to the unit. you might find a blown control circuit fuse. controls are 24 volt ac.

[djw]

no outside thermostat

No... there isn't a bulb thermostat outside. Also, I did remember that there was one extremely close lightning strike 2 nights ago. The AC might not have run since then. I checked the outside fuse box and they look OK.

[HayZee518]

things may visually "look" ok but measure the voltage output from your devices - fuses, breakers. a square D breaker when it trips shows a red flag. GE, Westinghouse, Challenger, Crouse-Hinds, Arrow-Hart breakers when they trip assume the center position. Throw your breakers associated with the AC to the extreme off then back on and measure the voltage coming out, then go to your unit where the contactors are and measure the incoming voltage there. check for a blown control fuse or maybe a contactor overload that feeds a particular motor. usually a button to reset the overload.

[djw]

tested at contactor and at transformer

Thanks for your input. I reset the circuit breaker again. It is fine. I checked the incoming wires at the contactor and it was 120- 125 volts. The wires exiting sthe contactor showed 120-125 volts. I also found the tranformer and tested it. It showed the same. Nothing tested at 24 volts. There is a small fuse (like in a car) on the "integrated port glass" but I didn't check it. Should the contactor or transformer have tested at 24 volts?

[HayZee518]

That glass sae fuse is what I'm talking about. that is a control fuse. maybe your control circuit is 120 volts. solid state stuff usually runs at 24 volts where they are associated with burners and burner control as in gas controls. since we're this far into the circuit maybe you can send me a scanned picture of your electrical circuit.

[djw]

Thanks. I will check the fuse tomorrow. It should be easy to tell if it is blown. I'm thinking that the contactor is bad. They don't cost too much to buy so, I might try that. If the fuse is blown, does that mean something else is bad that caused it to blow? OH, and I will take a picture also at that time.

[HayZee518]

when the control fuse blows it means something in the control ckt is bad. a burnt contactor, a stuck contactor armature etc - a solid state motor controller like a triac is bad. the gateing circuit locks up so it blows a fuse

[djw]

back to the broken furnace

Well, I just replaced the contactor with one I ordered. The previous one was 6 years old.... but that did not fix the problem. I checked the fuse and it looks good... the little connecting wire in it is all in one piece.

These are some more things I checked.
1- the wires coming out the sides of the contactor show no volts. The yellow wires come out the left and the light blue wires come out the right side. Maybe that is normal. The wires from the house to the contactor show 120 volts and the black and white wire exiting the contactor show 120 volts.
2. there is a little red bulb on the "integrated port glass" but it is not lit.
3. there is 120 volts going into the transformer, but the yellow wire, light blue wire, and the light gray wire all showed no volts at all.

Nothing works. No heat, AC, or fan.
Thanks for any help you can give.

[djw]

oops forgot 1 thing

Oh, I forgot. I tested 1 more wire on the transformer- a red one. It tests 0 volts also.

[HayZee518]

if the primary reads voltage but the secondary reads zero in all cases, the transformer is blown - replace it.

[djw]

How do you know which is primary or secondary? White and black are 120. They are on the bottom. Lt Blue, gray, yellow, and red are on the top and read 0. Also, where can I buy a transformer part number B11416-43? The ones I find online don't have the same number of connectors on them. I think they only have 2 at the top and 2 at the bottom, but I have 4 wires being connected at the top.

Thanks so much.

Plus, I found the scan of the control board that you were asking for and am attaching it. (Thanks for your help. I had this installed in 01, replaced control board in 04 (under warranty, $100 labor), replaced heat exchanger in 06 (under warranty, $600 labor).... I need to understand how to fix the smaller things because it seems prone to breaking and no longer under warranty.) Plus, I may need to attach the scan to the next post. It isn't letting me add it here.

[djw]

scan of the control board attached