Have a carrier weathermaker 8000. Fan will not shut off even when I tunr the switch off. It still blows cool ait when set to Cool and hot air when set to heat. If I turn switch to off it still blows air. I think it could be relay or thermostat. Trying to locate both of those items in unit. Please help. Thanks in advance.:(

Remove the red wire from the thermostat. If is shuts down then, the thermostat is bad

Stupid question. Trying to find manual on-line. What does the TSAT look like? I see (2) red wires going to a small reddish circuit board

Not stupid. The thermostat tis the control on the wall that select the tempature and heat or cool. You can find onlone manuel for the thermostat at the sticky at the top of the heating & colling page here on this forum. A diagram should be posted on the inside of the panel of you furnace

Took faceplate off wall thermostat and removed red wire. Unit stayed on. Odd thing though if thermostat isn't bad why is it reading 84 degrees inside when I know it isn't 84?

Sound like the relay has stuck close as to why the fan is continuiously on. You can carefully tap it with the handle of a screwdriver. Sometimes this will release the contacts but I would replace as a permanent fis

Check the status light on the circuit board-should be visible through a clear viewer hole. If it is flashing look at the service label on front panel.

Didn't see any ststus lights on the circuit board. I am trying to fond what the relay might look like. Where should I be looking.

In your opinion would you say there is nothing wrong with the TSTA? Thanks.

The relay would be a small box like. Looks like it plugs into the board Look on the inside of the panel. Should be a diagram showing where it is.

Seem to have found 2 relays. One for the blower, which is where I believe the problem to be (blower not shutting off). The othe is a Hi/Lo Blower Relay. Not sure what that is. This is what the diagram said inside face of the panel.

Hi/Lo selects the blower speed. The one labeled blower is likely bad.

I am having a bit of difficulty removing the relay. Does it simply pull off the circuit board (ie like a plug from a receptacle)? I appreciate all your help. I do believe I am a heck of lot closer to solving this than before I started.

In all likelinees, it's soldered to the board and the control board is the replaceable part.
I'm not saying, it can't be replaced as a separate part, but unsoldering/soldering is a skill.

What's the make and model of the relay?

Does sound like contacts may be fused, tapping like above may separate contacts. Follow wires from blower motor to relay, that should be Hi/Lo relay. Relay feeding that should be blower relay. If board replacement Excessive, and comfortable with soldering and replacement relay not easily found, You could unsolder relay, solder wires to where relay was, and connect to new relay or contactor, Usually 24 volt ac coil.
Being on a board the coil could be about any voltage, should say on side of relay.

Relay manufacturer: Potter & Brumfiedl, Relay for Blower #T91R1D22-24-01, 30A 240VAC. Has uppercase C next to a small picture (symbol for a relay)on it and there is another set of numbers: 91-34. Where would I find parts? I probably would have to order, right?

You gentlemen mentioned tapping. Exactly what does that entail? Just hittinng the contact lightly with the screwdriver? I see what look like to be 3 recessed holes on the really. (1) goes east-west and is labeled COM. Then there are (2) more recessed holes going North South next to each other labeld NO and NC. The NC appears to be missing the contact. It appears as if the metal part of the NC contact is flush with th bottom of the hole of the relay. Could this be the problem or was it probably always like this?

Yes, physically tapping on relay body. Use insulated or keep isolated from other electrical connections to avoid shorting. If you are able to remove relay, measure continuity between common and Normally Open. Missing Normally closed contact may be intentional to cut cost, as it is not needed. There should be 2 more connections for the relay coil.
The 30 Amp/240 Volt is probably the contact rating. Coil is probably less.
If removing relay stops blower then either contacts may be fused or coil voltage present
At relay. Good Luck

Looks like that relay has been discontinued, probably because of the ROHS (Reduction of Hazardous substances) hoopla. Look here and see if something might substitute.

Potter & Brumfield Relays - Datasheets - Tyco Electronics

NO - means Normally Open
NC - Means normally closed
C - Means Common or the common contact

"Normally" means without power to the coil

The NC contact would not be used in this application.

This is, in effect, a definite purpose contactor. The contact rating (30A), the contact voltage rating, and coil voltage (likely 24 VAC). If you can't find the same footprint, any number of replacements should be available if your willing to move it off the board.

Electronic Components Distributor | Newark sell P&B relays, now manutactured by tyco/tyco electronics

The R8229A1021

Here:

United Refrigeration, Inc.

Would likely work.

The relay is held open with a spring, when the coil voltage is present, the armature moves toward the other contact. The contacts occasionally "weld" together over time. Tapping, separating and sometime burnishing (lightly sanding) the contacts will restore operation for a short time.

Thank you Stratmando and KeepItSimpleStupid but now I feel as if I have reached an impasse. You have been most helpful. I feel a bit helpless at the moment. You have both made me realize with 99% certainty that it is the relay for the blower that is the cause of my problem. My problem now is the fix is beyond my echelon of knowledge, meaning I will have to call a repairman. Of course this was what I was hoping to avoid. Thanks agqain and take care.

Well gentlemen, the tapping has worked! The AC unit is turning On/off as it is designed to. Thank you for your help.