We have a Rheem gas furnace/central AC system. The blower motor went out. We finally found a new one. However... I was stupid and did not draw the wiring diagram when I disconnected the old one. Now I can't seem to figure out how to rewire everything.

There is a relay switch on the side of the main furnace unit. The switch has a black wire and a white wire coming out the back of it. I'm sure they go to the little black and white wires comingout of the bottom of the "clump".

The "clump" (don't know the technical term) of connected wires that fit in the back of it has, on the front, 8 little spots, numbered 123 on top, 456 in middle, the bottom two say "coil". Blue wire out of each "coil", through to back of "clump". No worries on those.

#1 has a red wire, which I'm sure connects to the red from the motor.

#3 has a black, which I'm sure connects to the black from the motor.

#4,5 and 6 are empty and were empty - I believe should stay empty.

In case it matters, on the back of the "clump", there are 2 whites connected to W, 1 red connected to R, 3 connected to C, 2 connected to G, and 0 connected to Y. I did not change any of these.

Motor has a green (very short, maybe 6") ground, which I believe I can just mount to nearest metal casing?

Here's where I get confused: Coming up from the floor into the bottom of the switch box is one black wire which divides into two separate blacks. One of these is connected to the BROWN wire coming out of #2. The other.. I have no idea what it was connected to before, but I believe it was combined with two others in one connector. HELP ME! :eek: I have no idea what to do with this one! It's been over 100* for the past two-three weeks and we are MELTING.

I am not making sense of all that. Perhaps if I give some background, you can sort out that last black wire. Power comes into the furnace from the house as a pair of black and white wires. These will be fairly heavy wires, solid #14 or #12. They both must be connected to the blower relay and the primary of the control transformer. Anything else in the furnace, ignitors, powered draft, etc. must also be connected either to them, or powered off the transformer. There are also some limit switches and timers connected to the blower circuit.

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.

Most HVAC systems are set up to use a higher speed for air than heat. Thus, you have a black and white wire going to the relay, and several colors along with the white going to the motor. Some of the wires may not be used. Again, fairly large, but inside the furnace, stranded wires. Which section of the relay activates to give the speed needed, is determined by the white, yellow, and green coming back from the thermostat. Those wires should be much smaller and usually are solid, rather than stranded wire.

I am guessing the mystery 1 into 2 black wire is the power feed from the house wiring. One will go to the line side of the relay, and the other to something else needing power, perhaps the transformer. If this doesn't help, try to post back with more details.

Labman,

OK, I attached a crude drawing. The BIG BLACK goes into the bottom of that switch box and become 2 smaller, but still fairly large black wires. I was mistaken earlier - the two big wires out of motor are white and black (no red). I'm fairly certain the white goes to RED from #1 on clump and the black goes to BLACK #3 on clump. I'm also certain that the small white and small black on bottom of clump go to small white and small black from back of switch box.

So, the brown from space #2 is on the front of the "clump", is connected to one of the smaller blacks. Where do I connect the other part of the big to smaller BLACK (it is circled on the drawing)?

Hope my crude drawing helps you understand my even cruder descriptions (I don't know technical terms).

Thanks in advance for any help.

Since the blower only has 2 wires connecting to the motor, it is a single speed motor. How many wires did you disconnect? Unless you had to remove them for clearance, you shouldn't have needed to disconnect any wires except 2 to the blower. It would than be a simple matter of gathering together the 2 black wires, and whatever white ones and connecting them.

If you disconnected more wires, it may be a matter of tracing them down and seeing what they run to. The ''back of the clump'' looks like the standard connections for a thermostat. Are most of the wires connected to it the small solid wires, cabled together, and disappear in the direction of the thermostat? There also should be a pair of wires connected to the Y and C that run out to the coil of the A/C compressor. Check and see if you find the same wires at the thermostat and compressor. It doesn't have to be yellow, but you must have wires connecting the Y terminals and the A/C coil for the A/C to run.

Only Rheem can sort out the 1-6 on the front. There should be a schematic in the furnace. You could also check their web site.

I had to disconnect the little white and black to get the clump out far enough to disconnect the motor. Old motor had 3 wires; red, black, white, no green ground. Yes, all the ones on the back of the clump are the little tiny wires and seem to disappear to the thermostat. Nothing was connected to the Y before I started... Don't have a clue what goes there. I disconnected 4 connections- the small black and the small white from the switch to the clump, and two that went directly from the clump to the motor-the other wires (extra from motor and extra from floor) were somehow included in these connections.

So, black, to black to black? Meaning black from motor, big black from clump and black house power all together?

Oh! Just hit me-the two blue wires on the front, labeled "coil", go through the box to the back - apparently to the Y from inside.

And one more revelation (home from worked and looked it over again) - the house power is NOT the big black wire that splits into two. The house power comes into the switch box from above. It's a big flat white wire. I'm suspecting that the big, splitting black one is going to the AC unit outdoors. That's my best guess.

Just need to know where that extra black from the split goes.

OK. I connected little white to little white, little black to little black, black from motor to black from clump, white from motor to red from clump. Did not connect extra split black to anything. Turned on power. Thermostat working- can hear the click when we adjust temp, but blower not coming on.

Don't connect the house black wire to the motor black wire. The motor would run continuously. The house wire connects to the line side of the relay. Connect the black wire from the load side of the relay to the motor.

You may have a problem. If your old motor had a black, red, and white wire, it was a 2-3 speed motor. With only 2 wires, the new motor may not have the right speed for both heating and cooling. You might do better to return it and get the correct one. If not, you would also need to connect the wire that went to the red wire to black wire on the motor.

You need a wire from the transformer that goes to both the gas valve and the coil of the compressor. That could be the large black double wire, even if usually it is a small blue wire.

OK. I went back to the furnace room again. I removed yet another panel and found a wiring schematic of which I can make neither head not tails. It has several options, gives no idication of the meaning of the numbered slots on the clump.

But - I also traced the wires. I think this may be the rest of the information you need to tell me what to do.

Under this bottom panel, I found a small box above the pilot light area - this small box has a square (about 1 1/2") on it with two contacts, one TR, one TH, and a round contact. From the round contact, there is a copper wire going down where the pilot light is. From the TR side is a medium black wire which goes to the C contact on the back of the "clump". From the TH contact, there is a tiny black wire going to another box (may 3"x4", labeled Honeywell). This Honeywell box has two contacts. One has this tiny black wire from TH, the other has a black wire to a 1" square metal box, then out again to the W on the clump. From BOTH of these contacts on the Honeywell box, come the two medium black wires, which then become the one big black wire, which then divides to become the two again. One of these two is still connected to the brown wire, which goes to the #2 on the front of the clump.

The rest of the info on the "clump" is that there is one tiny red wire coming from R to the thermostat group. The C has one of the blue coil wires, the medium black wire from TR side of the box at the bottom of the furnace, and a small black which goes down beside the natural gas pipe on the outside of the furnace. The W has a brownish wire going to the thermostat group and the little black one from the Honeywell box. The G has black to thermostat group and blue to coil. There is also a black wire that connects to a yellow in the thermostat group - this black wire goes with the other to the natural gas pipe.

I believe the whole thing was jury-rigged to be single speed even when there was a 2 speed fan installed.

So - I have 9 wires not connected:
The leftover black from the big black which comes from the Honeywell box.
The white from the switch (from the house power)
The black from the switch (from the house power)
The red and yellow striped from space #1 on the front of the clump
The black from #3 on the front of the clump
The small black from the bottom of the clump
The small white from the bottom of the clump
The black from the motor
The white from the motor

I did try taking my drawings and the schematic to the AC places in town - hoping to find someone who could look at it - they are all closed on Saturday. It's 102 today. Sure would like to get this working, even if I have to manually turn the blower on and off. So if you can help me know what to hook up the blower to work and the AC to come on, I'd be forever grateful and can call a serviceman to fix it right when I get some cash.

I did make a new and better drawing, but I can't load it - too big. If you have an e-mail address where I can send it, I'd be happy to do so. I'll also keep trying to upload it to a website and will post that site if I have any luck.

Here's a site where you can see my drawing:

http://hstrial-glinkel.homestead.com/index.html

Thanks. Ginger

You could connect the blower directly to the house wire. However, you still must have power to the transformer, and 24 volts from it to the compressor outside. The transformer may be one of the boxes the house wires go to. It will have 4 wires or contacts, the house power in, and 24 volts out. The 24 volts should be the red wire to the thermostat and another wire to C. If you can get those 6 connections working, the A/C should work as long as there is power to the furnace. Just turn it on and let it run until the house is cooled off. Turn it off then and back on when the house heats up.

Once your have the house below 80, perhaps the schematic will make more sense.
I am afraid you are going to have to figure it out or pay somebody to fix the mess. Does it show sort of a box with all the numbers and letters from the relay in it with wires going to them? Do the 2 terminals marked coil have a line connecting them that makes several tight loops? Are a couple of the numbers marked L1 and L2? L2 will be the white wire from the house. L1 may pass through some limit switches. The box outside of the furnace marked Honeywell may switch off the main power in if it overheats. 2 or 3 more of numbers should show little circles connected to the blower motor.
On the schematic, the transformer will look like 2 of loop things together like the one for the coil. See what you find.

Labman - can't thank you enough for your patience and perserverance and help. I wired the blower directly to house power, got enough connected to make AC unit come on.

THERE IS COOL AIR COMING IN THE VENTS! HALLELUJAH!!

Will take my drawing to one of the electricians where I work and see if they can help me figure out the final correct connections - otherwise I'll give in and fork out the cash for a professional.

Thanks again - I think we might be down to 85 in here by this evening, after never getting below 85, even at night, and never below 95 inside in the day!

Thank you, thank you, thank you!