First, Thanks to all who suggested possible problems to check on my Coleman Mach 15,000 AC unit. So I checked the start and run capacitors and they are in spec. To be sure I even swapped them out with new ones and no change. Checked all wiring and no loose wires. Swapped circuit breakers and still no change. There is 115 Volts at the wire where it connects to the compressor but it wont start. Is it likely that the compressor has seized up on a unit that is only 5.5 years old and has not seen very much use? So now I ask, is it fixable or am I better off just buying a new unit?Your opinions please.Thanks Steve

If the compressor is seized I would expect the breaker to trip

One more test you might try is to disconnect both motor leads and ohm out the motor making sure the motor is not open.

darsben1 wrote:If the compressor is seized I would expect the breaker to tripYes, the breaker trips but it is confusing to me because sometimes the breaker at the source trips and sometimes the breaker in the trailer panel trips.

Have you measured amps and volts during the event?Otherwise you may as well take it in to the shop.

Mandalay Parr wrote:One more test you might try is to disconnect both motor leads and ohm out the motor making sure the motor is not open.If seized thermal overload opens in most cases so appears as an open winding. If tripping breaker then you need to check if compressor windings now have continuity to GND & you need an ohmmeter that has MEG-ohms range .You might get lucky & just be loose connection at breaker.

AC Still not working---Update--- | Good Sam Community

MEXICOWANDERER
Explorer
Sep 20, 2017
j-d wrote:
This is a 15,000 BTU, not a 15 Amp unit. We have one, and it's on a 20A circuit within our RV panel, 30A coach.

The question seems to be: Is the Compressor Locked (Stuck)?

There are three Amperages related to a compressor:

Starting, AKA Peak Inrush. This could be 50A or more and it takes good equipment to measure it. My cheapie Horror Fright clamp-on AC Ammeter cannot capture that.

Running, probably around 10-12A. Cheapie WILL capture that.

LOCKED ROTOR AMPS, Along with Running Amps, will be on a plate or label on the Compressor. LRA for this Mach 15 A/C is probably around 50A. Cheapie WILL capture this amperage.

But what usually trips on LRA, is an INTERNAL cutoff within the Compressor.

IF IF IF the RUN Capacitor is bad, Compressor will go into LRA and trip off on the internal protection. Very many tries, the Compressor will get HOT and it takes a LONG time, say half an hour, to cool enough for another try.

So, I recommend this: Disconnect Power and let the compressor cool while you get an Ammeter. Then, be on the roof, at the compressor, Ammeter clamped on input power, and have a helper turn the system ON. See what the Amps are. IF it's LRA, you have only seconds to read it before the internal trips the power off. You want to be on a full power shore tie, no extension cords. Give the Compressor its best chance to start.

Possible Hail Mary: I've seen this work, albeit rarely. Compressor COLD. Again, on max available AC power: Same as the AMPS test, but this time you're next to the Compressor with a RUBBER MALLET. Line up a clean shot at the upper end of the Compressor where you won't hit a line, wiring or component. Have your assistant turn the system on and Smack the Compressor a split second later, before the internal will open the circuit. As I've said, odds are against this but I've seen it work. Odds? My speculation is 5-10 pct. But it's sure a cheap try.

Kudos for a jammed packed reply. I have cut and pasted it. Thank you :)
57_Panhead
Explorer
Sep 30, 2017
Well thanks again to all who responded with tips and advise. Turned out that the AC unit was bad and I replaced it with a new one from PPL Motorhomes. I was able to install it myself and works like a champ.

Steve
j-d
Explorer II
Sep 30, 2017
Congratulations on a Conclusion, and Thanks for letting us know!

Sorry it took that, but in so many places, Lost A/C ==> Trip Canceled. My DW is like that. If the A/C doesn't work in a car, it might as well not start. Might as well be up on blocks...
JoeH
Explorer III
Oct 01, 2017
57 Panhead - I had 2 AC units fail within the first year - first one the compressor locked up, the second one, it would short cycle. Both replaced under warranty.

Do you have a 57 Pan ? I have a 53 ( with 57 tanks) that I've had since the late 60's
57_Panhead
Explorer
Oct 02, 2017
JoeH wrote:
57 Panhead - I had 2 AC units fail within the first year - first one the compressor locked up, the second one, it would short cycle. Both replaced under warranty.

Do you have a 57 Pan ? I have a 53 ( with 57 tanks) that I've had since the late 60's

I do have a 57 Panhead, it's a 1960s period correct Frisco style chopper with foot clutch and suicide shifter, kick start only, old school.
wa8yxm
Explorer III
Oct 02, 2017
Is it likely the comnpressor has sized on a 5.5 year old.. NO
it is possible YES

NOTE: HOw often do you clean the condenser coils.... Faiulre to clean puts more stress on the compressor.

Forum Discussion

AC Still not working---Update---

About Technical Issues

Related Content

Brakes not working - Update

CareFree Awning Stop Working .... Update & fixed

Air horns don't work. update: DUH!

Hood Vent Fan No Longer Working - UPDATE

How to Work Hydro-Flame BRC10 Controls? Update #2