The outdoor unit is working perfectly. When I turn the cooling on, everything starts up fine. When it cycles off and back on again, the blower motor doesn't start back up with it. So I'm turning it off myself and waiting a while to turn it back on. After turning the cooling off, nothing will start again for 3-6 hours. Turning the cooling back on yields no result. No compressor, no blower fan. Turning just the fan on has the same effect, nothing. I've taken readings with my multi-meter and everything looks normal, but nothing turns on. None of the electrical connections are loose or broken. Transformer is outputting as it should. I'm guessing that the blower doesn't restart with the system because the capacitor is getting weak but I don't understand why it starts after sitting for several hours but not before. Maybe there is a sensor that is keeping the whole unit from starting up. I'm really baffled.

Model Unit: Carrier fb4cnf030t00 acaa

Any help is appreciated.

 

Welcome to the forums.

Not quite clear there.

If nothing...... inside or outside..... comes on..... check for a float in an overflow pan under the air handler or in the drain line near the air handler. Usually that switch is setup to just shut the outside unit down but it could be wired to shut everything down.

 

the float is fine. I cleared the line after winter and haven't had a float problem since. I'm thinking maybe a relay problem as well but it works sometimes and not others. I have checked the float when it doesn't and it hasn't been an issue

 

Even if the blower motor had an issue.... the outside unit should still operate.
This is a heatpump system... correct ?

I would check for 24vac on the R and C terminals.
When unit is calling for A/C there should be 24vac between C and Y and C and G.

I think the link I posted below is your unit. The FB4 starts around page 40.
http://www.refripartesrd.com/uploads...e%20Manual.pdf

 

Hey Pete, thanks for the reply.

This is a heat pump system yes. I have 28V across R&C and when the unit calls for cool I get 28V across C&Y and C&G. The compressor and outside unit start just fine but the blower fan doesn't. Yesterday I was able to get the blower fan to start with the heat, and it stayed on when I switched the system to cool and turned the thermostat down appropriately.

 

The 28vac across R and C is always live power.
28v across C & Y and C & G mean the stat was calling for A/C and blower.

This is the confusing part..... or is it incorrect ?
Is it nothing or not everything.

 

so what usually happens is when I set it to cool, everything comes on except the blower fan. If I set the heat, the blower does come on with the heat and will stay on when I switch to cooling. The fan was occasionally coming on when calling for cooling but it's not at all unless I call for heat. Once I turn the heat on I switch over to cool and the blower stays on and the cooling comes on. Could there be a capacitor each for heat and cooling that is starting the blower for heat and not cooling?? That doesn't sound right to me but that's the way it's acting. I know this is really weird. That's why I'm so confused

 

It sounds like you need a new control board for the indoor unit. Heat is a normally closed circuit to a different control so the blower works in heat mode.

 

Oh ok. Is there a way to test the control board with simple tools, ie a simple multimeter? Thanks.

 

Ok, so I found the problem. It was indeed the control board. Turns out, a lizard had crawled behind it, electrocuted himself, and died there, shorting terminals out and causing very weird behavior. Got him outta there and things are working fine again. Thanks for all the help guys!

 

Wow....usually not only the intruder gets fried..... so does the board.
You're lucky. Thanks for letting us know how you made out.