When our front Coleman A/C/Heater unit went on the fritz less than a month ago we were worried that the compressor had gone out in it. We were also a bit concerned about how much this would cost us. You see one night after I had gone to bed Sharon switched on the front electrical heater unit and she heard a loud humming noise and noticed a bad smell that she thought might be something burning.
So she woke me out of a dead sleep, much to my dislike. However, smelling something burning is not something to take lightly in an RV. So after waking up a bit and trying to analyze the situation I had deduced that the heating unit was bad and that we likely lost the compressor. I assumed the hum was the compressor trying to start and the smell was it getting too hot. The burning smell reminded me of a smell I had experienced before when a motor had burned out.
So the next morning I started reading the internet to see what I could do to further troubleshoot the situation. Everything I had read pointed to the start capacitor and not the compressor. Well if this were the case it would cost a whole lot less than replacing the compressor. I called a electrically astute buddy of mine and we climbed up on the roof and removed the A/C cover and unscrewed the 6 screws that were housing the start and the run capacitor’s (above left photo). Nothing appeared to be burned or scorched but after removing the retaining screw on the band that held the capacitors in place there it was… two burnt spots on the start capacitor (above right photo in the bottom right edge of capacitor and on the cap lower edge of it).
A email to Tiffin verified that this was a 88-108 mfd start capacitor and the likely culprit and this replacement part from Tiffin was $36.00. A call to the only RV parts place in town resulted in them having one for $38.00 and it was in stock. I picked up the capacitor and my buddy and I replaced the suspected bad one in the front A/C, Thanks, Jimmy! Then with fingers crossed I turned on the A/C and viola…. no hum and no burnt smell. We now have a perfectly functioning front A/C just in time for the predicted 80’s temperatures forecasted for this weekend. After all that hard work Sharon and I paid a visit over to one of our favorite College Station restaurants, Los Cucos, to get our favorite Gallitos Fish Plate…. mmm mmm mmm mmm mmmm……….
NOTE: You must be careful some capacitors will require discharging before removal otherwise a jolt of electricity may be discharged through you when removing it. A useful document on Capacitors can be found here.