cancel
Showing results forย 
Search instead forย 
Did you mean:ย 

Dometic AC compressor

powellmj
Explorer II
Explorer II
On our bedroom AC unit when you first turn it on, you can hear it click and the fan starts, then it seems like it lugs down trying to start the compressor. It will then run for about 3 mins and then makes a very loud noise. I took the top cover off and cleaned all around, even brushing the fins with a tool. Had my wife turn it on with me on the roof and the noise is clearly coming from the compressor. I read something about a "kick-start" or "hot start" option for compressors and I wanted to get your opinions. I'm on the house hookup with a dedicated circuit and surge/drop protector, power is not the issue. It happens at 72 or 95 degrees outside. Yes it's out of warranty by a few months. Thanks in advance for reading all the way through.
26 REPLIES 26

powellmj
Explorer II
Explorer II
Really appreciate the quick replies and it seems the pricing on the hard starts units are not too bad; so I'll give that a try. Thanks again and I'll update sometime this coming weekend.

LittleBill
Explorer
Explorer
I love how 6 people recommended hard start kits...

how exactly does this fix the problem of it running fine then in 3 minutes a loud bang?

the unit obviously has issues.

dougrainer
Nomad
Nomad
Learjet wrote:
my bedroom dometic came with a hard start kit in it from the factory...not sure about the other unit...I need to check it out next time.



If you are talking about the small PTCR device in the pic. That is technically a Hard Start device. BUT, it only can be used once in a few minutes. It MUST cool down after the initial start. So, if you have a compressor that starts and then shuts down within a few minutes, that PTCR will NOT be utilized for the restart of a short cycling compressor. Once the PTCR cools down, it WILL initiate a boost for the Capacitor. So, that PTCR is not a good true Hard Start component. You really need a true Hard Start Capacitor kit for best results. But, better than nothing. Doug

Jennifer_Koper
Explorer
Explorer
i'am also looking for a highly technical team or concern of AC regarding issue for my home in nearest @ Los Angeles.

it will be appreciated if anyone could advise me / please share with me your experienced if you faced suck kind o problem earlier.

PNW_Steve
Explorer
Explorer
If I understood the original post the a/c worked previously and then stopped. If that is the case, a hard start kit would be unlikely to resolve the problem.

A failed start cap is definitely worth looking into.
2004.5 Dodge 3500 5.9 Cummins, NV5400, 5" turbo back stainless exhaust, Edger programmer & 22.5 Alcoa's
2002 Forest River 36 5th Wheel (staying home)
1992 Jayco 29 5th Wheel (Mexico veteran & headed back)
2002 "faux" Wanderlodge 40' My new toy....

Learjet
Explorer
Explorer
my bedroom dometic came with a hard start kit in it from the factory...not sure about the other unit...I need to check it out next time.

2017 Ram Big Horn, DRW Long Box, 4x4, Cummins, Aisin, 3.73
2022 Jayco Pinnacle 32RLTS, Onan 5500, Disc Brakes, 17.5" tires
B&W Ram Companion

wa8yxm
Explorer III
Explorer III
One of the things I will never emotionally understand is why the !@#$@#$@ they do not install the hard start caps at the factory

Academically I know the an$wer to that que$tion but ala$... $tupid they are.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times

Chris_Bryant
Explorer II
Explorer II
They do not install start kits any more, just install one and odds are it will be fine.
-- Chris Bryant

larry_cad
Explorer II
Explorer II


try one of these. they work
Today is my personal best for most consecutive days alive.

Our Travel Blog

DFord
Explorer
Explorer
I'd check the start capacitor. It would be round in a black plastic can maybe 3 or 4 inches high and about 1-1/2 or so around. If it shows any sign of something coming out of it, it's bad and needs to be replaced along with the start relay that controls it. Some use solid state devices these days instead of relays. Replace the capacitor and it at the same time. The start capacitor is only meant to be in use less than one second to get the compressor started and then must be disconnected to wait for another start. If the relay fails to disconnect the start capacity as it should, the capacitor will quickly overheat and be ruined. The compressor's start windings could be ruined at the same time so don't keep trying it. The capacitors are a lot cheaper than replacing the whole unit if the compressor burns up.
Don Ford
2004 Safari Trek 31SBD (F53/V10 20,500GVW)
'09 HHR 2LT or '97 Aerostar MiniVan (Remco driveshaft disconnect) for Towed vehicles
BlueOx Aventa II Towbar - ReadyBrake Inertia Brake System

PNW_Steve
Explorer
Explorer
Typical roof airs do not have service ports. In my experience problems with the compressor or refrigerant loop generally find you replacing the roof air rather than repairing.

I have seen some handy folks add service ports and repair refrigerant leaks and recharge with good success. Not a task for us mere mortals. ๐Ÿ™‚

Good luck.
2004.5 Dodge 3500 5.9 Cummins, NV5400, 5" turbo back stainless exhaust, Edger programmer & 22.5 Alcoa's
2002 Forest River 36 5th Wheel (staying home)
1992 Jayco 29 5th Wheel (Mexico veteran & headed back)
2002 "faux" Wanderlodge 40' My new toy....

Flute_Man
Explorer
Explorer
I would call a regular AC tech and have them check it out
.Jerry Parr
Jerry Parr
05 Mandalay 40B
Cat C7 350
04 Honda CR-V
Ham Radio K7OU
Retired EE
Jrparr32@gmail.com
602-321-8141
Full-timer