[OurHouse]

So today was the day to fire up the A/C and we're getting nothing. Error code is 2 yellow flashes and 4 green flashes. I've surfed the net, trying to decipher it, but I'm not finding it. Please tell me this is minor.

 

[yuri]

Where are you seeing the code? In the viewing hole on the furnace or air handler door?

If so the codes are on a sticker on that door or the back of it or in the owners or install/service manual.

 

[OurHouse]

Furnace area, but the codes aren't posted, and I don't have the manual.

 

[yuri]

Very strange. Every Carrier furnace I see has them on the front or back of one of the doors. Did you remove both doors and look?

Post the model # of the furnace or air handler as you now have the AC. Then we can try find the codes on the net.

Code 24 on the older units is a blown 24 volt fuse. There should be a 3 amp purple GM plastic auto fuse on the circuit board in the furnace. However you need to check the wiring outside to make sure a dog or rodents did not chew it and cause a short.

 

[OurHouse]

Here's the outside unit specs

 

[Bitters]

That's the model number of the outside unit. Is the blower running inside?

 

[OurHouse]

Nope. Blower isn't doing anything. I was really hoping to DIY this fix, because I have 70% pay reduction in the summer time.

 

[OurHouse]

(I should say, absolutely nothing is happening. )

 

[Bitters]

OK, Go to the furnace and find the sight glass on the panel cover. Check to see if the LED is flashing. Count the flashes and then take the cover off. The codes should be on the inside of the cover.

What is the model number on the furnace?

 

[OurHouse]

The codes aren't on the inside

It's yellow, yellow, green, green, green, green.

 

[Bitters]

You can find the model number in the top compartment of the furnace. Let us know.

 

[OurHouse]

So I do believe I found another model number for the furnace... sloppily written it's either S8mvp100-20 or 58mvp100-20 or that lady part could be -zo.

 

[OurHouse]

Grrr. So whoever installed this thing was a moron. None of the labels were as they should have been, but I finally located the codes, and the "secondary voltage fuse is open." So I pulled the 3 amp fuse out, replaced it, and momentarily all became right with my world. Then it blew again. It ran for , hmm, 5 seconds.

 

[supers05]

Check for shorts in the wiring, especially the low voltage wiring outside. Take the thermostat right off the base plate. If it still blows then it's something inside the furnace.

Cheers!

 

[beenthere]

Turn thermostat to off. Replace fuse. If it doesn't blow in 5 or 10 seconds, turn thermostat to fan on(if fuse blows with thermostat turned off, short is in thermostat wires, thermostat, or furnace control board, or board area). If fuse still doesn't blow. Check outdoor unit for a short.

 

[OurHouse]

So I put another 3 amp fuse in, with the system off, and it was fine. I switched it to heat and turned the temp up and ran heat, and it was fine, so as a novice I'm still trying to figure this out... I just don't have the money to give up...

If anyone spots a good trouble shooting video, point me to it. I borrowed a real nice digital multimeter, but I never learned much on their use. I mean , I've added wired boxes for lights, but never successfully did intense troubleshooting, YET. YET.

 

[supers05]

Ok, so it's your a/c. We have ruled out your furnace internals, the thermostat, and the wiring in between. Now it's just the wiring out to your a/c and the condensing unit itself. (the a/c outside) Take a look for chewed wires outside. Then if you don't find any bare wires, turn the power off to the outdoor unit and take the electrical cover off of the unit outside. You'll likely need 5/16" nut driver. (sometimes it's a Phillips or 1/4") Do this with some caution because there's a chance that there's criters in there making a nest. If no criters, take a picture and post it.

Cheers!

 

[BayouRunner]

Disconnect both low voltage wires to contactor. Turn ac on, if it doesn't blow the fuse, replace the contactor. Coil is shorted out

 

[OurHouse]

So there's this thing... it says it doesn't contain fuses, but when I pulled it out and put it back in, this other adjacent box started with (error codes?) lights

 

[OurHouse]

This is the second item I referenced...

and when I opened it to see if wires were all intact, the red flashing light stopped because I think the thing has acontact verification point so it senses being opened . (Metal on each side comes together or spreads apart when opened.)