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View Full Version : Blower not working when a/c is turned on


drchef
Dec 23, 2008, 11:46 AM
I turn on the heater and everything works fine, I turn the fan to ON and everything works as it should, but when I turn the a/c on the only thing that happens is a noise from the unit like fluid running through it however the blower does not start, this is with the blower in the ON position and the heat off a/c switch on OFF, however as soon as I switch to a/c the blower turns off and it makes the same noise mentioned above. I have tried to jumper r-g, r-w, and r-y with the same results

KC13
Dec 23, 2008, 11:53 AM
What type of thermostat? Sounds like a case of bad switch contacts.

drchef
Dec 23, 2008, 11:59 AM
Thermostat is a Ritetemp model 8035c. I thought the contacts were bad as well, but when I jumper the contacts at both the thermostat and the unit the same thing happens

KC13
Dec 23, 2008, 12:03 PM
Okay, give us a li'l more info... system type, brand and model #'s. etc.

drchef
Dec 23, 2008, 12:08 PM
Lennox Elite Series G24M4/5-100A-12. Gas furnace, not to familiar with HVAC systems, so don't quite know what info you are looking for

KC13
Dec 23, 2008, 12:17 PM
When you jumpered/un-jumpered R-Y, did you see a rather large/bright spark? If the outdoor unit contactor coil is partially shorted, it could be hoarding control voltage while still functional.

drchef
Dec 23, 2008, 12:22 PM
It does not spark at the thermostat, but it does at the unit, but I would not call it a large/bright spark

KC13
Dec 23, 2008, 12:26 PM
Try this: disconnect wire from R at indoor unit, then with R-G jumpered, jump R-Y. What happens?

drchef
Dec 23, 2008, 12:29 PM
With R disconnected won't I simply be jumping G-Y?

KC13
Dec 23, 2008, 12:30 PM
Try this: disconnect wire from R at indoor unit, then with R-G jumpered, jump R-Y. What happens? Re-read and follow as posted.

drchef
Dec 23, 2008, 12:49 PM
At the indoor unit with R disconnected and R-G jumpered, then jumping R-Y the same thing happens, the blower is on with r-g jumpered then when I connect r-y it turns off and the only sound left is the small wooshing sound. The spark you previously mentioned, while I still wouldn't call it big, it is much bigger than than anything I get from r-g

KC13
Dec 23, 2008, 01:16 PM
I would check the outdoor unit contactor coil - see if it looks burned. The test you just performed is strengthening my "hoarding" theory... disconnect power to outdoor unit first.

drchef
Dec 24, 2008, 09:43 AM
How do I locate the contactor coil and what does it look like?

KC13
Dec 24, 2008, 01:38 PM
It is the primary control relay for the outdoor unit. If you disconnect the power supply and remove the control compartment cover, the incoming power supply wires should take you right to it. The coil is the fine winding usually visible near the base. Ideally, a check of the coil resistance and/or amps is the sure thing, but if it appears obviously burned no test is necessary.

wmproop
Dec 24, 2008, 02:21 PM
Its to cold for a/c

drchef
Dec 24, 2008, 02:28 PM
That wasn't the question now was it, and how do you know it's too cold do you know where I am?

wmproop
Dec 24, 2008, 02:42 PM
Smile,be happy,a little humor and Christmas cheer goes a long way,, Baa Humbug, I hate it when people can`t take a joke,, I`ll remember your name in the future,:(:(

KC13
Dec 24, 2008, 03:11 PM
That wasn't the question now was it, and how do you know it's too cold do you know where I am?If it's a/c you're needing right now, I'm jealous...

drchef
Dec 25, 2008, 12:14 AM
New Orleans-It snowed here for the second time in 30 years and two days later I was in shorts