upnorth15
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Re: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: I am sure they know about their product, BUT what happens is that "people usually talk two different languages"... :-) they talk "technology / product" while you talk "user / product". Sometimes things don't "translate well". You can likely follow their direction and get the AC model number from the actual outside unit (this is the big thing on the roof)... maybe a 5XX, or 6XX. However, the controller / relay board is usually inside for ease of access / repair. If you look at your picture of the plate, it indicates that there is wiring leaving the "box" and going up to the AC UNIT. There is also wiring coming from the thermostat and going into the "box". Knowing what AC unit they installed will help as then when you look at the controller, it should be correlated as a "companion part". IF you get a chance to talk with a technical person again at dometic, then the question to ask would be "what connections do the colors align with on the label?"... in your picture, you see the color codes of the wire and the connections saying "to thermostat"... each color aligns with some function going into the controller. As you saw in your picture of the thermostat, one can readily see a color to "function" for the wiring. What you need is that "equivalent" description from the label on the control box. IF those don't align, then you will having wiring "mismatch issues" which might be the source of your problem. IT is strange that two AC units are operating the same way (ie. fan always on). It is unlikely that there is a component failure, more than likely a wiring error or possibly a relay card "mismatch" (unlikely but possible). From the dometic documentation, I am not able to determine the "color to function mapping". If you get this, it may go along way to solving your problem. In terms of warranty, the AC unit (on the roof) and the controller (inside ceiling housing) are likely replaced together so indeed, it is a warranty issue if either fail. Your problem is the warranty probably doesn't cover "labor" which your "friends" don't appear to want to do for free (in terms of further troubleshooting). That's the "between the rock"... :-( Thanks again!! I haven't gone looking any further into this because the girl I bought it from said she was going to raise some hell with the dealer. And she did. They are big farmers in the area so ......... Now they've agreed to drop labour charges and if there are parts the girl I bought it from will split costs with me. So hopefully dometic will cover under warranty. Like you said because this is happening with 2 AC's it's likely something deeper going on. Your info is so great and if you don't mind could I pass it along. I just wonder if these guys know what they are doing!! Still I'm wondering if I even needed a new AC. One more question? Does a bad compressor in AC typically blow the main breaker in trailer?702Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: OK... thanks for the testing data. It does sound like the control board might have an issue similar to the other link I posted. The control board has a couple of different relays, one could be an issue or as the previous poster indicated, the physical position of the board in the box is such that it is touching something that it shouldn't be (inspect carefully). The two screws on the plate expose the innards of the box which then will get you the number. Remember to turn off the breaker before playing with the box! Ok thanks. Is this control board typically not part of a new AC install? Possibly the guy at Dometic is mistaken thinking this is under warranty as well. I was told to find the model number by going to AC outside on drivers side and open cover.702Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
upnorth15 wrote: budwich wrote: upnorth15, the wire removal that was suggested won't impact the fan starting up with the AC switched to on or at least it shouldn't.... the system should work normally.... in "actual normal wiring", typically only 4 wires are used and fan control is NOT wired. Those wires are used only for "direct" control of the fan. If you disconnect them at the thermostat as suggested, then the switches for fan control (specifically) will do nothing. If the fan still operates as in your problem, then the issue is likely somewhere else... as suggested by hornnumb2, in the control box area maybe. Hello again and thank you again. I will try this and keep you posted. Should I just tape off those 2 wires? AC Fan still runs after unhooking the two fan wires. I called Dometic and they said whatever is wrong is covered under warranty including a control board. Now I just need the model number.701Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: upnorth15, the wire removal that was suggested won't impact the fan starting up with the AC switched to on or at least it shouldn't.... the system should work normally.... in "actual normal wiring", typically only 4 wires are used and fan control is NOT wired. Those wires are used only for "direct" control of the fan. If you disconnect them at the thermostat as suggested, then the switches for fan control (specifically) will do nothing. If the fan still operates as in your problem, then the issue is likely somewhere else... as suggested by hornnumb2, in the control box area maybe. Hello again and thank you again. I will try this and keep you posted. Should I just tape off those 2 wires?702Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
Hornnumb2 wrote: You might check the metal box that holds the control board. (The part that has the wiring diagram on it.) I have had 2 that I have purchased that the standoffs inside the box that hold the board are broke and the pcb shorts against the metal case. You can try to pull out that one bolt holding it and flip it over to see if you hear it moving around in there. Please do with breaker off as there is 120v in there. Thanks for your reply. We can certainly check that. Can a short be causing the AC fan to run in OFF mode? This is the main problem.701Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: ooops... ??? not sure why the "No thanks Ozlander. " His suggestion is good. It will likely stop the AC fan from running all the time and will likely just have the fan running ONLY when the AC is on. oops is right... sorry guys I took that all wrong.... but what else is new. Sorry Ozlander I apologize. So walk me thru this. I unwire both the "fan" and "hi fan" wires from thermostat. So when I use the AC how will the fan run then?701Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
Ozlander wrote: The first thing I would do is disconnect the orange and blue wires from the fan terminals on the thermostat. Then we can go from there. Sorry I was way off base there. Sorry about that.. :? So is this disconnect of wires fan and hi fan helping with troubleshooting the problem? I'm game if you can help me with the walk thru from there.253Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: no problem. If you can post a picture of the wiring at your thermostat (pull off the cover) so that you / we can see the terminal and wire connections. We might get an idea of what your next steps might be... ie. chasing wiring or otherwise. According to some dometic wiring, there should be 6 wires at the thermostat. Less may mean that some "mods" were done previously instead of running additional cabling.... and those "mods" may not have been as "expected". here's a pic252Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: :-( I think they had a "couple of issues" ("onion skin" so to speak). The AC problem had some issue since it was blowing fuses (likely a motor issue / compressor problem) but the "fan on" issue was also there all along which might still be a wiring error (either at the thermostat or AC box), since it is likely that the "installer" might have only did a "unplug/plug" and things "worked" thereafter (ie. no fuse blowing). Anyways, I don't see an easy way out without doing some good wiring investigation which will take time and understanding which will mean $$ if you don't do most of it yourself. :-( Too bad the country is so big ... :-) That's for sure!! Might be cheaper to fly you out here to fix it. The wishy washy poor customer service seems to be the norm anymore. You've been great and educated me so I've got some knowledge of what might be going on when I talk to them again. Thanks again Kathy253Views0likes0CommentsRe: HELP----AC fan blows when thermostat is set to OFF
budwich wrote: OK... so now you are getting to the "root cause" of the problem... although you didn't indicate why the ac was changed out. Basically, there are "considerations" when trying to wire an AC unit in a travel trailer. The heating / furnace work on 12v systems entirely while the AC needs 120v... so there are different relay "options" that need to be used. Dometic offers a "few" different ones. Overall, the system is relatively simple in terms of electronics and tracing IF you have a little electrical knowledge and a meter. My guess based on my limited experience converting / adding a digital thermostat to my system (which is coleman based I think). The fan selection / speeding will not having any effect on the furnace operation as the furnace control takes care of it all. Basically, the thermostat just causes an "ON/OFF" function based on the temperature. The AC side has more "considerations". My old dometic analog only had heating (two wires only) so I don't have much more to go on other than what I have read on the various sites. Again, you need to look at the wires that are at the thermostat (copy down the terminal and color) then "trace" this over to the "jumble" and see which colors show up there, and then even further, you need to see which wires go where inside the AC "box" where the relays and others terminals are. From there, it will likely be possible to understand the issue... hopefully. I guess depending on what the "work order" was with the install company, their stance of "it will cost you" is probably "reasonably" IF it was stated as "replace my AC UNIT" which they did. It appears that the "real problem" was never addressed or "paid for" to get resolved. Thank you so much for all your info. It is very helpful. They were told to fix the AC. We never told them to replace it. The girl that works at this RV place was the seller's best friend.(girl we bought it from) She just told us they would look at the AC and fix it and said it might have to be replaced. They told us it was the compressor!! and also told us they tested the system.252Views0likes0Comments
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