View Full Version : AC/Heat/Fan Won't Start
GlastronGuy
10-03-2003, 02:10 PM
I came home from work and my home AC unit wasn't running but still turned on. I tried the heat and fan to see if they worked but neither one did. There is power to the unit.
I'd like to jump the thermostat connections on the unit to eliminate that as a possibility but I don't remember which of the 4 wires to jump. Anyone know?
Mandelon
10-03-2003, 02:16 PM
The red one. No, Wait ! The blue one. No, the red one. Is there a white one? Cuz it could be the white one....
:D :D
I think Trailer Park Casanova is the resident HVAC expert????
NorCal Gameshow
10-03-2003, 02:16 PM
check to see if you're getting voltage to your t-stat..
NastyOne
10-03-2003, 02:18 PM
You mite want to check and see if the rotator-splint is still good.
[ October 03, 2003, 03:20 PM: Message edited by: NastyOne ]
NorCal Gameshow
10-03-2003, 02:25 PM
on mine, red is power, green to the fan
NorCal Gameshow
10-03-2003, 02:25 PM
double post, none for over a year....
two this week :mad:
[ October 03, 2003, 03:27 PM: Message edited by: NorCal Gameshow ]
JetBoatRich
10-03-2003, 02:26 PM
The door on the Furnace/blower may be open(usually inside a closet). There is a safety switch on the front of the unit when the door is slightly off it will not start.
Good luck :D
GlastronGuy
10-03-2003, 02:29 PM
JetBoatRich:
The door on the Furnace/blower may be open(usually inside a closet). There is a safety switch on the front of the unit when the door is slightly off it will not start.
Good luck :D Thanks, already checked it and it's working.
leibniz
10-03-2003, 02:31 PM
Be very delicate cutting the wires. Cut them 1 at at time until they are all severed; staring with the black one. But first, make sure the ticking has stopped. Be careful not to sweat, as this may cause a short in the wires. Now carefully dismantle the device until it is free from it's surroundings. Use extra caution while disposing of it, as there may still be some reactive material inside.
And most important of all; watch out for the "sonofabitch" who might be lurking behind you.
GlastronGuy
10-03-2003, 02:35 PM
leibniz:
Be very delicate cutting the wires. Cut them 1 at at time until they are all severed; staring with the black one. But first, make sure the ticking has stopped. Be careful not to sweat, as this may cause a short in the wires. Now carefully dismantle the device until it is free from it's surroundings. Use extra caution while disposing of it, as there may still be some reactive material inside.
And most important of all; watch out for the "sonofabitch" who might be lurking behind you. You talking about this guy?
http://www.***boat.com/image_center/data/500/395bomb.jpg
leibniz
10-03-2003, 02:44 PM
Yes I am. :D
burbanite
10-03-2003, 02:52 PM
This sounds like a job for TPC.
Trailer Park Casanova
10-03-2003, 03:05 PM
Unplug the furnace before you touch the control wireing on the t stat.
Then plug the furnace in to see if it runs.
If it's not your stat, then let us know what kind of furnace you have, and approx what year it was installed.
Don't jumper any controls inside the furnace,, just the low voltage wires in the stat.
leibniz
10-03-2003, 03:08 PM
Check the circuit breaker. Sometimes they trip. eek!
GlastronGuy
10-03-2003, 03:09 PM
Trailer Park Casanova:
Unplug the furnace before you touch the control wireing on the t stat.
Then plug the furnace in to see if it runs.
If it's not your stat, then let us know what kind of furnace you have, and approx what year it was installed.
Don't jumper any controls inside the furnace,, just the low voltage wires in the stat. Red/green wire?
Trailer Park Casanova
10-03-2003, 03:31 PM
Most problems like you describe are either no power to the furnace, no 24V to the thermostat s, or the t stat is bad.
Thermostats don't fade away,, they die instantly.
What kind of furnace do you have,, and I can tell you how to test it.
GlastronGuy
10-03-2003, 03:34 PM
Trailer Park Casanova:
Most problems like you describe are either no power to the furnace, no 24V to the thermostat s, or the t stat is bad.
Thermostats don't fade away,, they die instantly.
What kind of furnace do you have,, and I can tell you how to test it. It a Day & Night "Even Temp" installed in July of 1996.
The thermo is a Honeywell T8112C1007
There is power to the AC/Heat unit and the service panel disconnect on the unit is working.
The thermo shows the time and temp but I assume that portion is battery operated.
Trailer Park Casanova
10-03-2003, 03:37 PM
Jumper R to Y and tell us if the fan comes on.
GlastronGuy
10-03-2003, 03:43 PM
Trailer Park Casanova:
Jumper R to Y and tell us if the fan comes on. Nope, no fan. frown
Trailer Park Casanova
10-03-2003, 03:48 PM
OK
Open the panel to the filter compartment,, their should be a circuit board in there.
Look closely at the board for a purple ATC 3 fuze.
Automotive type,, or any other fuze on the board.
Check to see if the fuze is bad.
Trailer Park Casanova
10-03-2003, 03:51 PM
We're going to check everything that is free and simple first.
GlastronGuy
10-03-2003, 03:55 PM
Trailer Park Casanova:
We're going to check everything that is free and simple first. :)
I didn't see it before, it was buried under the wiring harness and covered in dust. It is burnt out. can we get one at an auto parts store?
[ October 03, 2003, 04:56 PM: Message edited by: GlastronGuy ]
Trailer Park Casanova
10-03-2003, 04:01 PM
Yep.
Don't fake it. Get the exact fuse (get several).
But first:
Make sure the furnace is unpluged, then reconnect all the wireing to the t stat and put it back together smartly before you do any other work.
Do all work with the furnace unplugged,, then when youre completely done,,,you can plug the furnace in and run it.
GlastronGuy
10-03-2003, 04:04 PM
Thanks, wife went down to pick up several, I'll post when I put the fuse in.
GlastronGuy
10-03-2003, 04:28 PM
Put the thermo back on the wall in the off position.
Installed new fuse.
Plugged in power cord, fuse OK.
Pushed in disconnect switch, fuse OK.
Turned on unit from thermo and fuse blew. frown
Mandelon
10-03-2003, 05:09 PM
Well that's it then, time for a new furnace. The transmorgrifier is decompatulated. When the J.B.R.imator overloads to the Casanovator, the Riverdavulator causes an immediate break in the 454yalation diode. It will cost $4300 and I can do it in 9 weeks. But you havta send the deposit now. For parts, ya know.
:D :D
When you turned it on did you activate the heat, the AC or just the fan?
DansBlown73Nordic
10-03-2003, 05:18 PM
idea Maybe some tin foil will fix the problem!!!! eek!
JetBoatRich
10-03-2003, 05:26 PM
Mandelon:
Well that's it then, time for a new furnace. The transmorgrifier is decompatulated. When the J.B.R.imator overloads to the Casanovator, the Riverdavulator causes an immediate break in the 454yalation diode. It will cost $4300 and I can do it in 9 weeks. But you havta send the deposit now. For parts, ya know.
:D :D
When you turned it on did you activate the heat, the AC or just the fan? very creative, LOL
GlastronGuy
10-03-2003, 05:39 PM
That GD Riverdavulator is always effing things up!
I pulled the fan motor thinking that it comes on whenever any other system comes on so that might be it. It wasn't. My wife was outside near the evaporator when I turned the system back on and she heard something happen there before the fuse blew again.
Mandelon
10-03-2003, 05:49 PM
I have a shut off box out by my AC condensor. It has a couple of old fashioned large fuses in it. They have blown on occasion.
It sounds like you are troubleshooting properly. Keep eliminating problems and it will be whatever is left.
Sometimes it is a short on the motherboard and is simply not an owner serviceable item. :(
Sounds like TPC went out to Parker....sorry we are not more help.
GlastronGuy
10-03-2003, 05:59 PM
Mandelon:
I have a shut off box out by my AC condensor. It has a couple of old fashioned large fuses in it. They have blown on occasion.
It sounds like you are troubleshooting properly. Keep eliminating problems and it will be whatever is left.
Sometimes it is a short on the motherboard and is simply not an owner serviceable item. :(
Sounds like TPC went out to Parker....sorry we are not more help. It's down to the evap fan or the compressor.
Tomorrow I will eliminate the evap fan from the equation and see what happens. Thanks for all the help.
Trailer Park Casanova
10-03-2003, 06:00 PM
No,, not yet,,
Longshot chance it's bad circuit board, posibbly somethng else:
This is beyond homeowner repair and I suggest you have a qualified tech come out and diagnose it.
Look in the yellow pages for Carrier, Bryant, Day & night. These brands are common,, and the service person will get you taken care of.
But,,, check as much of the Thermostat wire as you can between the furnace and t stat looking for points where it may have been pulled too tight and has come exposed,, shorting out.
Disconnect where the wire comes into the furnace,, and if the board fuse still blows,, then you know it's internal.
Yep,, I do see that in the field.
If not,, call a pro.
[ October 04, 2003, 06:23 AM: Message edited by: Trailer Park Casanova ]
Check the stat wires outside at the unit and see if the dog chewed them. If not check your stat wires in the attic, sometimes the rats or mice will get up there and chew the insulation off and short the wires out. A bad board usually will not take the fuse out. Give me a call if you want 909-545-0958 or at Modernair in Corona. Hal....
[ October 03, 2003, 09:09 PM: Message edited by: Hal ]
GlastronGuy
10-04-2003, 11:55 AM
The magnetic contactor is not engaging on the evap unit. I can engage it with a screw driver and the unit comes on.
Is it powered up by the start capacitor? Could that be bad?
You talking about the contactor in the condensing unit outside? Have you ever got your fan to operate using the stat with the heat cool switch in the off position? If you can't turn the fan on with your stat then you still don't have 24 volts and nothing will work.If your fan will turn on with the system switch on the stat in the off postion then your problem is in the stat wiring going to the cond. unit or your coil is burnt out on the contactor outside.How many wires do you have going to the stat and what color are they? Like I said before just call me and I'll walk you thru it. Hal...
[ October 04, 2003, 01:38 PM: Message edited by: Hal ]
GlastronGuy
10-05-2003, 11:03 AM
Well, my AC unit is afraid of Hal. I got him on the phone and it started working. :)
Thanks, Hal and thanks TPC.
Have a beer on me.
http://www.sdro.com/plum/beer.gif
GlastronGuy
07-03-2004, 07:16 PM
AC is down again.
It sounds like the compressor is humming. The capacitor does have a bulge in the top of it.
Sounds like the run cap is bad. The reason the caps bulge like that is to keep them from blowing up. When they get hot and are ready to blow the top pops up and opens a set of contacts inside the cap and takes it out of the circuit. You will need to replace it. Two of the main causes of that happening are low voltage and the compressor not being off long enough for the system pressures to equalize.(takes about five minutes to do that) So if you don't have a time off timer in your unit controls or stat aways wait 5 mins to turn your unit back on after it shuts off. If you have a volt meter you can check your voltage. Should have a min. of about 200v which is low but will still work. It works best around 220v. If its low call the power company and they can boost it for you.
Freak
07-04-2004, 05:23 AM
Yep 9 times out of 10 the 5 doller cap is bad on the unit and the guys you call from the phone book tell you that the whole unit is bad.
GlastronGuy
07-04-2004, 05:49 AM
Thanks. I'll pick up a cap and go from there. The fun part will be trying to get one today, the 4th of July.
:(
GlastronGuy
07-04-2004, 06:26 AM
I didn't have to discharge the cap.
Is this normal?
GlastronGuy
07-04-2004, 07:43 AM
Originally posted by HOSS
Hot start kit.
Which involves.......?
Flying Tiger
07-04-2004, 07:38 PM
Whats the rating on the cap?
I might have one in stock you can have.
I Might.
Flying Tiger
07-04-2004, 07:39 PM
Originally posted by GlastronGuy
I didn't have to discharge the cap.
Is this normal?
If it's bad, yes it's normal.
If it shocks you, you will be:
1. Mad at the world.
2. Never need Viagra for the rest of your life.
Its should cost you around $20.00
GlastronGuy
07-05-2004, 06:35 AM
There are two numbers on it.
7.5uf and
35uf 440 VAC
Other info:
+06 -06% 50/60Hz
I tried searching for it by the numbers on it but I came up with nothing.
Flying Tiger, not getting shocked was the one thing I remembered.
:)
http://www.***boat.com/image_center/data/500/395cap.jpg
If any place is open, I will try to pick up one this morning.
GlastronGuy
07-05-2004, 04:05 PM
Apparently, that cap I have is a 2 cap unit.
35uf and 7.5uf.
I found a shop open but he would have to order the same unit and it wouldn't be here till Thursday. I wanted AC now.
He sold me 3 different units and drew up a wiring diagram.
I installed the units and the AC worked for about 15 minutes and then the compressor quit. The fan stayed on this time, I assume because of it's own cap. Now I assume the compressor is bad. I gave it a couple of good whacks with a dead blow hammer and then used a 2X4 and framing hammer. No joy.
This is how he had me wire it. Does it look right?
http://www.***boat.com/image_center/data/500/395WiringAC.JPG
NorCal Gameshow
07-05-2004, 04:19 PM
if it wasn't the compressor, it probably is now...
I checked my A/C manual it didn't show any hammers or two by fours as the preferred tool...
think of all the money you're saving on electricity:D
GlastronGuy
07-05-2004, 04:35 PM
Originally posted by NorCal Gameshow
if it wasn't the compressor, it probably is now...
I checked my A/C manual it didn't show any hammers or two by fours as the preferred tool...
think of all the money you're saving on electricity:D
We must have different manuals...
I am saving on electricity but I am spending more on beer. Plus, I took this week off work to chill. That's impossible, now.
Flying Tiger
07-05-2004, 07:01 PM
It's called a 35 by 440 capacitor.
Very common.
Call around and see if a A/C parts house is willing to sell you one.
They run about $70.
That wiring diagram looks little screwed up. Comp and herm mean the same thing. (compressor). On your old cap the letters mean.
C= common H= hermetic (compressor) and F= fan (fan motor)
With 3 caps it should look like this
http://www.hotboatpics.com/pics/data/500/55run_cap-med.bmp
BTW your old capacitor is called a dual run capacitor 7.5/35 uf 440 volt. They cost around $25.00. Retail should be around $45.00
GlastronGuy
07-05-2004, 08:01 PM
Thank for the info guys.
I'll double check the wiring.
GlastronGuy
07-05-2004, 08:36 PM
Well, it's time to get a pro out here. I re did the wiring, turned on the unit and the compressor started up.
I went into the house, closed all the windows and settled in. After 5 or so minutes I went outside to double check and the fan wasn't moving and the compressor was vibrating wildly. It was so hot I could smell the paint cooking off of the unit.
The guy today told me it would be about $1200 to do a 3 ton unit. Does that sound right?
Thanks again for the help.
You probably just have a bad condenser fan motor. Probably runs a while, heats up and shuts off. Then the head pressure goes up and your compressor gets very hot. But it should be OK if it was still running. That may be why the first capacitor went out.
$1200.00 is a pretty good price for a new3 ton condensing unit installed.
GlastronGuy
07-05-2004, 09:25 PM
$1200 was to change out the compressor.
Oldsquirt
07-05-2004, 09:39 PM
Chris, I don't know how old your system is, but you may want to price out a complete replacement instead of just a compressor. Either way you go, make sure that they thoroughly flush the lines, condensor and evaporator. If the compressor died it may well have sent debris though the whole system.
GlastronGuy
07-06-2004, 05:05 AM
Craig, the system is 8 years old this month.
Whats the name and model # of your unit?
GlastronGuy
07-06-2004, 06:52 AM
Day and Night
Model AC1CN036-B
One estimate for $1750
and one for "around $1500"
EDIT:
Two more estimates
1800
and 1900 - 2100
We went with the 1750 because he can do it today.
Thanks again for all the help. You guys are great.
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