Coleman A/C Issues

[mattf76]

Hello,
New to forum, hopefully someone can help. I purchased a 04 Fleetwood Wilderness 28ft travel trailer few yrs ago. Last summer while camping, my A/C unit quit. I was running off of my generator and it ran low on fuel and began surging. The A/C worked fine up until this point and a friend filled the generator and tried starting it while I was away while thermostat was still set on a/c. The fan turns on when click to a/c and will run but the compressor doe snot seem to start. I've heard of capacitors going bad etc.. I was wondering if anyone could help or give some direction on trouble shooting. The A/c unit is a Coleman I believe. model number 8333B6664.
Thank you.

[mattf76]

Thanks Chris.. I did take the board to a local electronics shop they said one leg of the relay is bad. the leg for compressor. I found relay for 3-12 bucks. they can also get one and repair it as well as test the board. I am going to go this route first. if new board is indeed needed, do you have a part number and price for a new one. my model number is listed in first post. Thank you for your help.
Matt

[Chris_Bryant]

Sorry I was busy today- it does sound like the board- the relay could be bad, and can be replaced if you are comfortable with circuit board work, but the boards are still available, and come with a new box, board and freeze sensor.

[mattf76]

I did the checks and I have 12V to mini board from thermostat in all places. hi fan low fan, cool high cool low. and 12V between B & Y posts. All of the checks on the 9 pin connector shows good with exception of posts #1 & #3. I'm only getting a reading of 6 VAC between them. I tried with the freeze sensor unplugged and also with a jumper wire across the posts and still only have 6 VAC. Is it safe to assume the control board is bad or the compressor relay on the board is bad? Any further things to check for from here or is a new control board needed. also are they available still?
Matt

[mattf76]

Thank you all for the replies. I will try these checks this evening..
Matt

[Chris_Bryant]

As Doug said- I believe every ducted RV unit has to use a freeze sensor, as the ductwork is often inadequate. Here's the most common Coleman setup:

[dougrainer]

Bob Landry wrote:

Chris Bryant wrote:
You should read 12 volts between the yellow (Y)terminal and the Blue (B) terminal on the upper unit- this is from the thermostat. If you do have 12 volts there, you can try jumping the freeze control (the small sensor that sticks in the coils). If this thermister is bad, it will keep the compressor from running as well.

He said the unit was a Coleman. Do they also have a freeze sensor?

Yes, they do. Doug

[Bob_Landry]

Chris Bryant wrote:
You should read 12 volts between the yellow (Y)terminal and the Blue (B) terminal on the upper unit- this is from the thermostat. If you do have 12 volts there, you can try jumping the freeze control (the small sensor that sticks in the coils). If this thermister is bad, it will keep the compressor from running as well.

He said the unit was a Coleman. Do they also have a freeze sensor?

[Chris_Bryant]

You should read 12 volts between the yellow (Y)terminal and the Blue (B) terminal on the upper unit- this is from the thermostat. If you do have 12 volts there, you can try jumping the freeze control (the small sensor that sticks in the coils). If this thermister is bad, it will keep the compressor from running as well.

[Bob_Landry]

Go back and jumper around the relay like you did before and let the compressor run long enough to see if it's going to cool. You won't hurt anything by doing that as long as the blower fan is running. BTW, the condenser is not powered, it has air blown through it at the same time as the evaporator with a single fan. If the unit blows cold air with everything running, then you have a bad control board.
Hang on to the caps you replaced. It never hurts to have spares. Everyone jumps on the start capacitors because they know nothing about AC units, but they read a "my brother-in-law had that problem" post somewhere on the Internet. In reality, capacitors just don't fail very often and when they do, it's usually visible like the can bulging or it's leaking electrolyte. In over 15 years, I have only had one or two that looked good and checked bad.

[mattf76]

I've replaced both the run capacitor and fan capacitor on my ac unit. The fan starts but I do not think the compressor or condenser is running. The air coming out doe snot get colder. If I switch to fan it stays same and if switch back to cool on thermostat I then get nothing and have to wait and fan will eventually start. I jumped the relay which I believe is start relay on the board. put the black and purple together and I can hear and feel vibration from condenser. and it will do this at the minute the breaker is turned on regardless of thermostat position. One put back together through relay I have nothing again. same difference shore power or with generator. Both used to power it up without issue before. Any other thoughts..? help..?
Matt

[mattf76]

Thank you. I replaced both the run and fan capacitors in it last evening and still does not start. fan blows fine but does not seem condenser is running. fan and all turn easily.
Matt

[islandvagabonds]

You can buy a kit that includes the soft start capacitor and a small device that bypasses the capacitor once running. About $40 and easy to change out. Call Camping World with you unit info they will have the kit. I had a similar experience not long ago.

good luck