I NEED ADVICE ON BLOWER WHEN AC IS ON

[redkmd]

Hi I am stumpped at the ac blower I can say now that my ac is cold working well in the desert keeps the house at 76 when 110 outside but every day at one point or another and today no exception except it has done this several time is the ac goes off then immediately the blower comes back on and dont go off even thou the ac is off and it will run till it gets hot air in the house most of the time if i turn the thermostat off and unplug the blower from the outlet and let it sit a little while then plug it back in and turn the ac on it is fine for the rest of the day usually.
Any ideas of what this could be would be appreciated because I called five ac companies and had five stories from them all as to what it is and cost wise from low to out of site to fix it without even seeing it.
Please let me know what this sounds like to you professionals.
thank you
I have a mother terminal 78 living with me and I need ac and cant afford a big bill right now.
Ron

[Robert]

Hi Ron,

I would suspect either a faulty blower relay or a faulty circuit board, whichever you have to control blower operation.


What is your furnace model number ?



Thanks for inquiring,
Robert

[redkmd]

I see coleman magnum furnace but where do I find the model number at? And is this something that I can replace myself without getting elecrocuted lol I am not to fond of electrical items and I know a capacitor or something like that on the blower cage can kill you if you dont know what your doing, and by the way I had an ac man tell me the same thing on the phone today as you did so he was honest at least.
I would love to fix it myself if possible but what if it has both is that possible and you replace the wrong thing, but if you can tell me where to find the model number I will and post it.
thank you

[redkmd]

This same guy also stated something about a sensor that determines temp that if to warm it goes on till it cools down what is he talking about but he said it most likely is the fan relay or circuit board like you said but I would love to be able to fix it myself if possible.
the problem is how do I know if it has one on it and where it is even at? to order the right thing i sure cant waste money on the wrong parts.
thank you
Ron

[Robert]

The model number will be on a data sticker/plate on front facing of furnace.

It will also have all data for furnace.


It will have blower relay or board, one or the other.


Fairly simple to replace.


Those sensors are usually in gas furnaces with standing pilot lights.


Thanks,
Robert

[redkmd]

I do have a gas furnace that I do have it is not electric, so what if it is that sensor? How can I know if it is the sensor in the gas furnace causing that or the board, and second how do I tell if it has a blower relay or if it is built on the board, by that I mean where is the relay located at if that is what it has? but again how would a person like me be sure wheather it is the board, relay, or that sensor in the furnace and is thte sensor a do it yourself or need a tech since it is gas?
thank you
Ron

[redkmd]

FOUND SERIAL NUMBER MODEL NUMBER ETC
It does not look that old to me but I am no expert so here is the numbers if that help you to help me at all I appreciate it

MODEL N0: DGAM056BDF

SERIAL NO: 981022048

Like I said it is gas so now to figure out how to diagnose correct if it has a fan relay, or board and if it could be a sensor that you said is in gas furnaces as I am not sure if this is electronic ignition or piolot on all the time, I sure appreciate help in getting the right thing to fix this.
Thank you

[Robert]

Hi,

Ok, your furnace was manufactured in Sept., 1981, so fairly old.


You would need a pilot light to have the sensor, yours doesn't so no sensor.


You have a control board in your furnace, not a relay.


To know if the board is bad, you would need to know how to test it with a multi-meter to determine if it was or wasn't sending power when needed.


Due to fact that the board is $172.00 + $8.00 shipping and you have a gas furnace, would be best to have a Tech diagnose correctly.


You also seem apprehensive and uncomfortable due to inexperience with this. That's perfectly natural, but could endanger you or lead to a misdiagnosis which can be dangerous as well.


If the Tech wants more than $172 + $8 s/h if it is the board, holler back at me.


I just don't want you to get hurt or buy this board and not need it.


Take care and best wishes,
Robert

[redkmd]

thanks for the advice, no I am not afraid of doing it I meant if it were a sensor inside the furnace that I was a little worried, the board I can see very easy to get at and take a digital photo of it and disconnect and put back on. I am only worried if it is not the board what else could be causing the fan to restart after it shuts off when the ac unit goes off and the blower comes right back on? I just dont want to have an ac idiot here and in arizona a lot of rip off artist since we are so hot tell you anything. I had several people tell me it seemed like a circuit board to them since it does it in the morning usually after cooling down all night so the odd thing is it looks new lol since furnaces dont get used but a few minuted here and there to take a chill out of the place in the winter never left on more than a few minutes in this climate. I would get the board in a couple weeks when I have the funds but hate to put that in and it be something else but again what else could cause this any other ideas at all?
thank you
Ron

[Robert]

Hi Ron,

At the board, you have input LINE voltage (120vac for gas and 240vac for electric furnace).


Then, you have input 24vac low voltage from t-stat signal.

This energizes relay coil on board which then closes contacts and allows the LINE voltage to continue.


You then have output LINE voltage to Motor/Run Cap.

When blower comes back on, test and see if you have 24vac at R and C.

If not, see if you have LINE voltage at Cool and Neutral.

If you have Line going to motor with motor running, BUT do not have low voltage 24vac at R and C, board relay is bad.

Replace board.

IF you have 24vac at board, then problem is elsewhere, possibly t-stat or short in wiring.

Now, with that said, I cannot gaurantee this as I am not there and not doing the tests.


Take care and best wishes,
Robert

[WildIrish]

Hi I am stumpped at the ac blower I can say now that my ac is cold working well in the desert keeps the house at 76 when 110 outside

For 20 years, I used to live in the desert, where the A/C would run for hours when temps exceeded 115.

Because of this personal experience, I'd strongly suggest (when you get this problem fixed) that you keep your A/C at a more reasonable temperature, like 80 degrees, in the future.

A/C units work VERY hard in the desert, so when you turn them down as low as you're doing, you're making it work even harder. That, and the huge waste of electricity (and HIGH electric bills!), are two reasons to turn up that thermostat. Wear lighter clothing, turn on fans (esp. a ceiling fan), do whatever it takes to keep cool...but turn that thermostat up to at least 80. That will not only reduce your energy bills, but also help your A/C's parts last longer, by not stressing the unit so hard during the most intense heat.