Coleman rooftop a/c

Bamshell wrote:
Finally fixed!! After buying a new control board and 2 thermostats it ended up being a $20 temp sensor for the coil which was actually the very first thing i looked at.. i tested both for continuity and neither had it so i ruled it out because 1 unit was working fine. Turns out i needed to ohm it out. The giod one had 11k ohms and the other was 80k ohms.. i swapped them out and then the unit worked.. in hind sight i see why it would let the heat pump come on and not the a/c. 6 hrs of trouble shooting and it was the very first thing i looked at. Oh well hope this helps someone!

You said in your first post HP function, the compressor would not come ON. Now you say it worked in HP mode but not in COOL mode. Doug

You state TEMP sensor for the coil. Do you mean the FREEZE sensor installed in the evaporator? If so, that part is NOT supplied when replacing a complete upper unit. And yes, that defective part will keep the compressor from running.

Finally fixed!! After buying a new control board and 2 thermostats it ended up being a $20 temp sensor for the coil which was actually the very first thing i looked at.. i tested both for continuity and neither had it so i ruled it out because 1 unit was working fine. Turns out i needed to ohm it out. The giod one had 11k ohms and the other was 80k ohms.. i swapped them out and then the unit worked.. in hind sight i see why it would let the heat pump come on and not the a/c. 6 hrs of trouble shooting and it was the very first thing i looked at. Oh well hope this helps someone!

swap control boards and watch the problem follow the board and then buy a new board on Amazon. Been there done that. I bet thats your problem

https://www.amazon.com/Coleman-83305191-Room-Sensor/dp/B019QH3QVC/ref=pd_lpo_1?pd_rd_w=vyZv9&content-id=amzn1.sym.116f529c-aa4d-4763-b2b6-4d614ec7dc00&pf_rd_p=116f529c-aa4d-4763-b2b6-4d614ec7dc00&pf_rd_r=P2HX6PHSZS3JNH10AAEV&pd_rd_wg=XePGw&pd_rd_r=86fca2e0-c465-4410-9407-8b92551a3e5c&pd_rd_i=B019QH3QVC&psc=1

It looks like this and can be brown also. It is usually located in the rear bedroom area on the wall. Some OEM's install on the ceiling, but this old of a RV it is probably on the wall or bottom of a bedroom overhead cabinet. Lack of or a bad sensor would not cause the problem he has. Doug

I have a dumb question. Where is the temp sensor for the rear or what triggers the rear ac/heat pump or furnace to turn on? Maybe the answer points to the solution. Both my last MH and my current MH have thermostats in the front and rear.

Bamshell wrote:
Thanks for all of the replies! Im leaning towards it being the tstat and here is why.. zone 2 is the back unit and if i switch to heat pump neither the compressor or the fan comes on. I am plugged into 50 amp ac now btw. If i go to cool, the fan comes on, no compressor. Also i just fired up my LP furnace and zone 1 seems to work perfect. When i try zone 2 on the gas heat it does nothing. I can tell there must be a separate fan for the rear zone because i have vents down low with no air flow coming out.. any feedback is greatly appreciated

At this point, you need to access your upper rear AC/HP control board. Check for loose or burnt wiring. You also need to check for 12 volts TO THE REAR FURNACE. The furnace is a separate appliance that is controlled thru the RVP tstat system. Did you replace the upper units or did a shop replace them? Either way, wiring may have been knocked loose when the upper control board was moved out of the way to replace the unit.

You can manually SWAP Zone 1 and Zone 2 at the front upper control board to test tstat operation for the rear HP. This link shows the ZC tstat wiring. Doug

https://www.airxcel.com/DesktopModules/RvProduct/Pdf/8330b331_8330b335_thermostat.pdf

Thanks for all of the replies! Im leaning towards it being the tstat and here is why.. zone 2 is the back unit and if i switch to heat pump neither the compressor or the fan comes on. I am plugged into 50 amp ac now btw. If i go to cool, the fan comes on, no compressor. Also i just fired up my LP furnace and zone 1 seems to work perfect. When i try zone 2 on the gas heat it does nothing. I can tell there must be a separate fan for the rear zone because i have vents down low with no air flow coming out.. any feedback is greatly appreciated

Your system (2005)

ENERGY MANAGEMENT SYSTEM -
SO AMP
Intellitec's Smart Energy Management System -
50 AMP (Smart EMS) is designed to be used in
RV s equipped with 50 AMP electrical service.
The system senses when the coach is connected
to a 50 AMP service or operating from the generator and allows simultaneous operations of all
the 120 volt loads. When 50 AMP service is not
available and the coach is connected to a smaller
electrical service, such as 30 or 20 AMP, the system automatically takes control of the loads to
practically eliminate circuit breaker tripping. It
constantly monitors the total amount of current
drawn in the RV and controls the loads, as necessary, to keep the total current to a value less than,
or equal to, the available power service.
There is no programming necessary and the unit
will work with any load within the circuit
breaker limits. The Smart EMS automatically
"learns" the amount of current drawn by each of
the controlled loads as it turns them on and off.
In this way, it automatically adapts to differing
loads or loads whose current changes with line
voltage or temperature.
Features:
• Limits total current to 30 AMPs.
• Minimizes circuit breaker tripping when
connected to 20, or 30 AMP service.
• Eliminates manual appliance select
switches.
• Senses current of owner added loads.
• Owner selectable 20 AMP operation from
remote panel.
• Protects air conditioners with two minute
restart delay.
• "Learns" controlled appliance current draw

Click this link for an in depth explanation.

https://intellitec.com/wp-content/uploads/2022/07/53-00894-600-1.pdf

When you do not have 50 amp service, just run your Generator to utilize it. Remember, on your year model, the EMS KNOWS if you are NOT ON 50 amp service and will kick out the bedroom Compressor from running. Your wall EMS display should show that. Doug

I believe i have the ems system you speak of, ill take a look. Will need to figure out how to use it if so