1994 Coleman Heater Model# DGAT056BDC Gas Heater

[cowboy81702]

I own my Mobile Home since 11/12/1994, I have not had any problems from my heater till this year. The problem I am having is the heater is working fine, but after the heater reaches it's temperature and shouts off the Fan Blower Motor keeps on running. What it is doing is coming on and going off, Kind of like it has it'd own mind now. At start up everything seems to work just fine, but from time too time the blower motor will turn off, and then turn back on. After the house has reached the temperature we have it set for, it will shout off like always, but now the blower motor keeps running. But only some times during the heater running will the blower motor shout off and then back on. But it's mostly after the heater shouts off dose the blower motor keep running. I am on a very low monthly disability income so any help would be very thankful. Ronald

[Greg]

Hi & welcome. It sounds to me like the fan switch may be acting up. this is a switch that tells the fan the chamber is warm and to start blowing the warm air through the ducts. It should not be too big of a fix.
Robert is much better versed in furnace areas than I am & I know he will add to this. Greg

[Robert]

Fan Switch # 7975-3281 is most likely the problem, but w/o testing can't be sure.


It can be seen and ordered through PayPal from left side of page here:http://www.mobilehomerepair.com/ColemanGas.html


OR, call toll free between 9A/4P CST Mon thru Fri to 1-877-263-7860 and charge to Visa or Mastercard.

You can test across the two terminals for 120vac when it does this and shuts the fan off.

IF it reads 120vac it is bad. IF it reads 0vac it is good and not the Fan Switch.



Thanks,
Robert

[cowboy81702]

Thanks for the information, I sure will be very happy if that is what it is since money is a problem. May I please ask yet another question on this heater where is the fan switch located. To be honest looking at how this heater is put together all the main parts are right in the front, there is a box about ten or so inches long, inside of it there are what looks like three relay, one of the relays has two wires going up to the blower motor. I just do not really no what I am looking for.
Thanks Ronald

[Robert]

Hi Ronald,

Inside that control box, look on back wall. Should be two small switches with two terminals each.

The one on the left should be the fan switch.


If you go to above reply link I gave, click on pic for enlarged view to

see the fan switch.



Thanks,
Robert

[cowboy81702]

Robert, Thanks for your help in this matter, it's nice to know there are still some people out there who really care. And are willing to reach out and help someone, . I went ahead and placed an order from I believe your web sight. I did test it and it was reading 117.8 Volts when the fan was running and while it was off as well. So I hope these parts will make it work right. You know whats so funny is when it comes to working on cars I am very good even if I deal with a lot of pain in my feet/legs and lower back. I am always willing to help someone in need of my help even if they can not pay me for my time. My wife gets so mad at me when I work on someones car for little or no pay at all, and this is because we are going through some really bad financial problems right now. But being able to help someone feels good, and since I have always lived my life like that I will not change now. Once again thanks, like I said this world needs a lot more people like yourselves. Thanks Ronald

[Robert]

Hi Ronald,

You're very welcome and thanks for the kind words and for ordering. Mark owns the website, I am an employee here in the HVAC forums.


Keep helping people when you can, it all will come back full circle.


I have never in 28+ years turned away from a HVAC call due to inability to pay when working for myself.


I am 48 too with two sons and am retired on disability from Law Enforcement with back and neck problems.

I also have diabetes and heart problems.


I definately know and understand where you're at.


I can't promise the fan switch will solve things, but it is most common for that.

Try this if it does it at least once a day. Jumper the fan switch and if it does not do it for a day or so, remove jumper and see if it starts again.


Take care and best wishes,
Robert

[cowboy81702]

Wow you two guys are doing a very good job helping people out. I am also sorry to hear you have back problems. I do not know if you deal with much if any pain, but my wife is always telling me I should try finding something to do with my life/time, it's so hard when all I do is hurt, my feet and legs hurt so bad that most of the time I can't even think about standing on them. I fought for my disability for eight years only to be put on a type of disability income that gives me only $613.00 Dollars a month. So although I keep trying to reach out and help people out on there cars as long as they buy there own parts so I do not have any out of pocket money, I will put them in for them and for the most part for little or no money. She gets so upset with me because it will make me hurt so bad the next few days. But like you two guys you have good hearts and that is really what this world needs. I have thought about trying to set up a web sight for people who have car problems, and I could tell them how do fix there problems for a small fee, something like five or ten dollars each time. I do not know how to set it up. Anyways God Bless the both of you and may all of you have a very Marry Christmas and a happy new years. Ronald,

[cowboy81702]

Wow you two guys are doing a very good job helping people out. I am also sorry to hear you have back problems. I do not know if you deal with much if any pain, but my wife is always telling me I should try finding something to do with my life/time, it's so hard when all I do is hurt, my feet and legs hurt so bad that most of the time I can't even think about standing on them. I fought for my disability for eight years only to be put on a type of disability income that gives me only $613.00 Dollars a month. So although I keep trying to reach out and help people out on there cars as long as they buy there own parts so I do not have any out of pocket money, I will put them in for them and for the most part for little or no money. She gets so upset with me because it will make me hurt so bad the next few days. But like you two guys you have good hearts and that is really what this world needs. I have thought about trying to set up a web sight for people who have car problems, and I could tell them how do fix there problems for a small fee, something like five or ten dollars each time. I do not know how to set it up. Anyways God Bless the both of you and may all of you have a very Marry Christmas and a happy new years. Ronald,

Robert, I got the new fan switch and new Pad, I am now having another problem. When I install the new fan switch relay, my heater will not turn on at all, the blower pump in running but my heater glow plug will not turn on at all. So there for the heater dosn't work,??. But if I put the old blower relay switch back in everything works just fine/ outside of the plower still running for a long time after the heater kicks off, and it is still comming on and off. I have tryed switching the wires around but still the heater will not work at all with the new switch you sent me. I know it's Christmas and I trully hope all of you are having a very happy one at that. But I need to know,? what to do with this new switch, and what if anything the problem could be if I install the new switch and nothing works, but it works with the old switch back in it. Thanks
Ronald K (505) 824-0330

[Phillip G]

what if anything the problem could be if I install the new switch and nothing works, but it works with the old switch back in it. Thanks

I would guess that you are replacing the Wrong Switch. You should have 2 switches. One is the FAN & the other is Lower Limit

The lower limit switch is "Normally Connected" and required to RUN the booster (Small) Motor & enable the Cycle Flame & Gas Valve. The Switch will open @ 145 Deg and disable/shut down. Markings on the switch L145-30F (Metal punched)

The Fan Motor Switch is "Normally OPEN" until heat reaches F110-20F when the switch closes. Markings on switch may be yellow Sticker with Part # and F110-20F

You can not Swap the switches

Hope this Helps,

[Robert]

Hi Ronald,

Let me get a wiring diagram and see what all you have in the circuit.


That fan switch has no bearing on furnace operation except for blower motor.


How many wires attach to it ?




Thanks,
Robert

[Robert]

Hi Ronald,

It has a Purple wire coming from A/C Relay #5 to one Fan Switch terminal.


Then, two Orange wires from other Fan Switch terminal going

to #4 and #9 holes of molex plug.


The Fan Switch has no bearing on the furnace operation.


You may be replacing the limit switch and not the fan switch.


If so, what you described is what would happen.


Put old switch back and replace the switch beside it with the fan switch.



Thanks,
Robert

[cowboy81702]

Robert, Wow call me dumb, and trust me there are a lot of times I am. Your right the switch I was trying to replace only has two wires attached to it. The one I was trying replace sounds like it's the lower limit switch and not the right one. So then if that is true, like I said I can be so dumb at times. So then there for may be there isn't anything wrong with the first switch you sent me. So don't send me another new one yet until I replace it OK. I am so sorry if this is my dumb mistake.
Thanks Ronald

[cowboy81702]

Robert, From what I can see on my heater system. If I am now looking at the right switch this time and not the so called lower limit switch which I was replaceing in the first place. Anyways the Fan switch in my heater has, Yes two orange wires, but not a purple wire but a light tan wire. So since you two have now told me I might of been trying to replace the wrong switch with the new one. But again the fan switch on my heater has the two orange wires but a light tan wire as well, dose that sound right,??

[Robert]

Hi Ronald,

Different furnaces have different wire colors. The purple is what the wiring diagram shows, but is often different from furnace itself.


The fan switch ~should~ be beside the other switch you were trying to replace.


Also, does that tan wire go to the a/c relay terminal #5 ?


Most likely it, just check where tan wire goes and is it located beside other switch or close by ?



It is only a dumb mistake if nothing is learned from it. If something is learned, it becomes a lesson.


I have a ton of lessons from this life, welcome into the club of everyone.


Take care and best wishes,
Robert