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HVAC guys, help please.

Gatorgrizz27

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May 20, 2020
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We have a 2 story house with upstairs and downstairs AC units. Heat had been working fine, even below freezing recently, but the system kicked off and wouldn’t come back on. Blower motor wouldn’t run in any position on the thermostat, heat, ac, or just fan on. Looked at the air handler and heard it buzzing, seemed like it was a bad capacitor.

Threw a capacitor in it tonight and it’s still not running, I poked around a little more and the buzzing was coming from the relay. I jumped the hot lead to the blower motor wire and obviously the fan will run, but the outside unit isn’t kicking on. I have two other small wires connected to the relay, I’d assume one is the trigger from the thermostat and then the other one tells the unit to run. Hooked them together an no change, then touched the one I’m assuming triggers the outside unit to the hot lead and got fireworks. :laughing:

Basis of my question is does the system work like I think it does, blower motor has to start running before the condenser unit will kick on? I’d imagine it has to to keep it from overheating or freezing up. Then, is it possible to jump something to get it to run for awhile and heat it up? I’ll shut it off and not let it run all night. Right now the blower is running with only the aux heating elements on, so it’s not doing a whole lot.
 
Pics of relay, I’ve already jumped the blower motor in the second pic.

39D5AC8D-6A5D-4A69-AE65-089B8464B335.jpeg
 
Well, your blue wire is obviously fucked
And what's with the duct tape?
Has this thing been :mr-t: rigged for a while?
 
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It has. I’ve never opened it up before but there’s a bunch of janky shit going on. Wasn’t cooling great over the summer so we had the coils cleaned and the refrigerant level checked but they didn’t check the air handler wiring.

Bunch of shit that goes to nothing, lots of corroded wire nuts also. Cleaned most of the connections.
 
To bad you didnt supply a model number or the interal wiring diagram to assist with helping anyone determine how it should run/be wired
 
What is the outside air temp?
 
Yes, heat pump with electric heating element backup. Can post wiring diagram and model numbers shortly, had to switch to grilling chicken and drinking.

It’s been getting into the high 30’s at night, last night it dropped to 60 downstairs with it not running. Assuming it will keep dropping if I don’t get it fixed, but the backup element is doing a bit. Bad news is the wife was sent home for the week due to Covid exposure so she’s got to sit upstairs in the bedroom or work in it.
 
Also texted the ac guy we use after the capacitor and fucking around didn’t fix it. I’m not dead set on a diy repair, but who knows how soon he’d be able to get to it.
 
D42B0C5C-6C6C-4DAB-AF09-936EBB74F24A.jpeg
Finally, the shitty ass rats nest of wiring. I did clean most of the connections.
 
And since I’ve been around and know someone will ask....



























realized I shouldn’t have mentioned the wife being cold. :flipoff2:
 
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Check the tab fuse on the control board. If that is good make sure your transformer is outputting 24VAC on the secondary (brown and red wires).

The fact that you lost the outdoor as well as the air handler at the same time usually points to the control wiring. Any janky bullshit like a skinned wire or a relay getting weak and drawing too much amperage will pop the fuse or smoke your transformer.
 
The copper ground wire is green, don't disappoint Abe-

Yeah I looked at that, but it’s pretty much just on the surface and the blower runs with that relay jumped.

Auxiliary heat brought the inside temp from 60 up to 67 so fuck it, I’m going to bed.

Whole thing needs to be rewired, hopefully the AC guy can get to it tomorrow.
 
Check the tab fuse on the control board. If that is good make sure your transformer is outputting 24VAC on the secondary (brown and red wires).

The fact that you lost the outdoor as well as the air handler at the same time usually points to the control wiring. Any janky bullshit like a skinned wire or a relay getting weak and drawing too much amperage will pop the fuse or smoke your transformer.

Did check the fuse if you’re referring to the one that looks like an ATO 12v auto fuse. Was good.

I’m fairly certain it is just a shitty connection on relay/sensor that went out. Can anyone confirm that the outdoor unit won’t start until the blower is on?
 
Did check the fuse if you’re referring to the one that looks like an ATO 12v auto fuse. Was good.

I’m fairly certain it is just a shitty connection on relay/sensor that went out. Can anyone confirm that the outdoor unit won’t start until the blower is on?

Percussive maintenance,

Op shits running nobody's freezing ac guy coming tomorrow! you just wanted to show of the bewbs,

Thanks
 
AC guy came out today, redid the ghetto wiring, and swapped out the relay. Ended up being a bad thermostat. Had actually crossed my mind to swap the one upstairs in but I’m assuming whoever rigged the air handler made some jumper wires and bent some pins over on the downstairs thermostat so I figured it wouldn’t work right anyways.
 
AC guy came out today, redid the ghetto wiring, and swapped out the relay. Ended up being a bad thermostat. Had actually crossed my mind to swap the one upstairs in but I’m assuming whoever rigged the air handler made some jumper wires and bent some pins over on the downstairs thermostat so I figured it wouldn’t work right anyways.

I would have told you that if nb I had read this last night. T stat should energize fan, reversing valve and compressor contactor on call for heat( most manufacturers) some energize reversing on call for cool. Glad you got it figured out.
 
Did check the fuse if you’re referring to the one that looks like an ATO 12v auto fuse. Was good.

I’m fairly certain it is just a shitty connection on relay/sensor that went out. Can anyone confirm that the outdoor unit won’t start until the blower is on?

Outdoor unit doesn’t care if the indoor fan is on.
 
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