RV

Have RV questions? Ask an RV mechanic online.

Connect one-on-one with {0} who will answer your question

Dometic unit with a new relay board and thermostate..compressor…

Customer Question
I just installed a 59516.751...
I just installed a 59516.751 dometic unit with a new relay board and thermostate. I can hear the relay's working but no compressor or fan operation. I checked the a/c line voltage to the relay board and the board is receiving 120 volts checked low voltage dc power board is receiving 12 volts dc any help as this unit will not work
Submitted: 11 years ago.Category: RV
Show More
Show Less
Ask Your Own RV Question
Answered in 4 minutes by:
7/6/2011
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Randall
Randall, RVIA Certification
Category: RV
Satisfied Customers: 28,178
Experience: RVDA/RVIA Master Certified Technician with many years experience.
Verified
Hi: Thank you for coming to Just Answer with your question. My name is XXXXX XXXXX perhaps I can assist you with this issue.

What was the relay board and thermostat numbers? You may not have compatible parts.
There are over a dozen variations of these. Get back to me and I can assist you. R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
all the parts have been checked by the manufacturer however the part nos are as follows: Unit 59516.751 dometic; (NNN) NNN-NNNN009 relay board and states the compatablity of the unit on the board and we have a dometic analog therostate and no heat strips and no heat pump straight a/c and a gas furnace
RV Mechanic: Randall, RVIA Certification replied 11 years ago
That should be good...........did you plug in the A/C to the control box? All wire colors matched up as per the diagram? This sounds like the cord to the A/C may not be plugged in. Check that and get back to me. R.J.
Randall
Randall, RVIA Certification
Category: RV
Satisfied Customers: 28,178
Experience: RVDA/RVIA Master Certified Technician with many years experience.
Verified
Randall and 87 other RV Specialists are ready to help you
Ask your own question now
Customer reply replied 11 years ago
I am a certified automotive technician, yes i checked the umbilical cord from the a/c done the connection i tight and all colors match. Took the cover off the roof top unit the blue lead going straight to the compressor is receiving 120 volts, the fan is receiving 120 vlts, it appears to me as though the equipment should be running. we need to get technical to determine whether the unit or control board is not functioning circuits voltages are needed to test individual circuits and wire colors where possible does this help to give you more informationcan you help me with this
Customer reply replied 11 years ago
did you receive my questions?
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Yes.............sorry for the delay as I was having a dinner break. The reading at the compressor would be more than 120 VAC. The start cap boosts it up to over 200 VAC.

Take the cover off the thermostat and see the wire marked "cool" and tell me if you have DC voltage there. That is what starts the compressor. Let me know what you have there.
R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
all terminals on all cap show 120 vac i checked the thermostate and the dc voltage is 10.2 milavolts at the cool terminal yellow and i checked the relay board at the yellow terminal at the stat wire and found 34 milavolts
RV Mechanic: Randall, RVIA Certification replied 11 years ago
That has to be over 8.3 VDC minimum...........you need to find out what the problem is there. Check the ground lead. Sounds like we are making progress. R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
I checked the ground and power to the circuit board all is good checked every thermostate wire for any 12 volt to the thermotat and found none sounds to me that i may have bought a bad circuit board. As far as the cap. are concerned, all i am seeing is line voltage 120 will that go up afte the start or should it be about 200 now could i be dealing with 2 problems
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Yes, you could............what do you have at the lead on the thermostat that says "7.5" as this will be the hot lead to the thermostat. If you have good voltage there, then the t-stat may be defective. It has happened before. And yes, the voltage to the compressor goes up on starting, but we need to resolve this first. If you have at least 8.3 VDC to the lead marked "7.5" you can jump that to the "Hi-Fan" lead and the fan should come on. Let me know what you have here. And just for being sure on the ground I would run another wire you know has a good ground up to that lug as well. R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
ran my own ground just to be sure and i checked 7.5 terminal and am getting 4.5 volts rechecked the terminal it is up to 7.6 volts
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Does it come on now or did you jump over to "Hi Fan" to try it?
Ask Your Own RV Question
Customer reply replied 11 years ago
no it doesn't come on and yes i jumped to hi fan and nothing
RV Mechanic: Randall, RVIA Certification replied 11 years ago
So there is another problem as well............do you get a usable voltage reading when you just turn the t-stat on to "Hi Cool" or "Hi Fan" without the jumper?
Ask Your Own RV Question
Customer reply replied 11 years ago
therm in cool, fan on high speed turn all the way down to freezing, using ground terminal on therm. for my meter 7.5 terminal reading 7.56, cool terminal 10 milovolts, furnace term. 17.2 volts, hi-fan terminal 130 milovolts, fan terminal 50 milovolts, just to be certain found 2 spare conductors in stat wire and used them for the 7.5 terminal and ground
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Sounds like a bad thermostat............those readings should have been nearly the same.
Should be under warranty..........R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
I understand where u r coming from and it sounds logical to me, my concern is that even though with all of this hooked up i can still hear the relays pulling in with no fan or compressor operation
RV Mechanic: Randall, RVIA Certification replied 11 years ago
Were these new parts? It is strange. You would usually get one or the other if there is good AC voltage............unless the breaker is opening up on load. That happens when they go bad sometimes. The slightest load causes them to open up but they still show good on the meter. One reason they want you to test the feed to the top with a light bulb. Go HERE for a copy of the Dometic A/C Service Manual and look at the testing they show. You might try that just to prove this out. R.J.
Ask Your Own RV Question
Customer reply replied 11 years ago
Looks like I am on my way to the parts store will reply tomorrow to let you know how it goes, it has been very nice to talk to another professional
RV Mechanic: Randall, RVIA Certification replied 11 years ago
You are welcome.............let me know what you find. R.J.
Ask Your Own RV Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a rv mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Randall Your Own Question
Randall
Randall
Randall, RVIA Certification
Category: RV
Satisfied Customers: 28,178
28,178 Satisfied Customers
Experience: RVDA/RVIA Master Certified Technician with many years experience.

Randall is online now

Related RV Questions
Atwood water heater not working on electric in Fleetwood
Atwood water heater not working on electric in Fleetwood bounder … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,932 satisfied customers
Dometic Duo Thermo heat pump when turn on cool, coil heats
Dometic Duo Thermo heat pump when turn on cool, coil heats up and blow hot air out. Wiring no issue, checked. What's wrong? … read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
I bought a new 15,000 btu domestic a/c unit for my camper. I
I bought a new 15,000 btu domestic a/c unit for my camper. I installed it today, got it all plugged it, and the fan will not come on … read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
2nd Second AC kept breaking the breaker when turned on
2nd Second AC kept breaking the breaker when turned on turning on I replace the board no longer does the breaker pop but the AC compressor does not turn on… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
To run my RV furnace, should I have 12volt coming from my PC
To run my RV furnace, should I have 12volt coming from my PC board in my ceiling when the thermostate is on … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,932 satisfied customers
I have a 2004 Forest River RV All American Sport 365 CKSS
Good morning, I have a 2004 Forest River RV All American Sport 365 CKSS and the air conditioner stopped blowing cold air. it still blows are, just not cold. My question is, what size unit is it? Thank… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
I have a Dometic Duo therm A/C with an Atwood hydro flame
I have a Dometic Duo therm A/C with an Atwood hydro flame thermostat. I think I had a power surge come through our trailer at a recent stop. The A/C would not come on. I did some trouble shooting and … read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
I have a Dutchmen Northshore travel trailer. When trying to
I have a Dutchmen Northshore travel trailer. When trying to run the ac it wont do anything, can hear a click once in a while in the unit. Checked breaker and tested for 110 power on the unit both insi… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
I needed a new t-stat for my 2010 Puma which was t-stat
I needed a new t-stat for my 2010 Puma which was t-stat number(###) ###-####000 but when I placed an order for one I was told that the part was now a(###) ###-####000. I ordered that part which looks … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,932 satisfied customers
Good day, My Rv is equipped with RM 3762 RB Dometic Fridge.
Good day, My Rv is equipped with RM 3762 RB Dometic Fridge. The Fridge is not working. There is no power going to the Fridge. It would appear the external 120 power is not covering to 12V. What could … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,932 satisfied customers
Randal, I have a 2002 montana 3575rl 5thwheel. I'm having
Hi Randal, I have a 2002 montana 3575rl 5thwheel. I'm having problems with my roof mounted ac unit. I have 12 volts from the thermostat, but no 110v volts.… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
Have a duotherm ac that on call the fan runs but compressor
have a duotherm ac that on call for cool the fan runs but compressor does not start. normally open relay on circuit board not sending 120 volts to compressor… read more
Michael Reush
Michael Reush
Master Technician
High School or GED
3,175 satisfied customers
Dometic AC unit will not start but there is a clicking sound
Dometic AC unit will not start but there is a clicking sound at the unit fan will not work either but furnace will kick on… read more
Michael Reush
Michael Reush
Master Technician
High School or GED
3,175 satisfied customers
2004 keystone zepplin z241 have a Dometic Duotherm model 57915531.has
2004 keystone zepplin z241 have a Dometic Duotherm model 57915531.has infared controls,all other systems seem to work.a/c fan comes on_unit kicks out-green light on(unit on) Flashing -a/c will not com… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
Dometic..cooling..my converter is only outputing 5.8 vdc
ihave a dometic DM2852 2 door refrigerator not cooling. i have found that my converter is only outputing 5.8 vdc. the refrigerator has a good 120vac supplied but the dc voltage at the two point termin… read more
gene
gene
RV Mechanic
Vocational, Technical or Trade Scho
1,100 satisfied customers
Atwood..The fan kicks on for abouth 20 to 30 seconds and then it shuts
My Atwood hydroflame 8500 IV series furnace will not light. The fan kicks on for abouth 20 to 30 seconds and then it shuts back off. The furnace never lights. all other gas units in the camper work… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,932 satisfied customers
Automatic..5-10 seconds, it switches to Segment 4, 5 and 6..ac
We have a Norcold N821FRT refrigerator which has quit operating. When turned on display indicates Automatic and after approx. 5-10 seconds, it switches to Segment 4, 5 and 6 bars. Also, if AC or Gas i… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
28,178 satisfied customers
Compressor..the Camper to the campgound electric plug leads..rubber
I have an issue with a Dometic Roof mounted A/C in my fifth wheel - About a month ago while camping It tripped the A/C circuit breaker and after reseting it I found the system only works if the fan sw… read more
Michael Reush
Michael Reush
Master Technician
High School or GED
3,175 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Highly recommend this RV expert. Prompt, good and detailed answers were given. Very willing to help with genuine concern. I will ask for him next time.

JackUSA

Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV.

DutchUSA

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

< Previous | Next >

Meet the Experts:

gene

gene

RV Mechanic

1,100 satisfied customers

28 yrs exp in the industry

Nick

Nick

RVIA Certification

664 satisfied customers

5 years RV repair and reconstruction, Fleetwood RV Training course completion.

Steve F.

Steve F.

RVIA Certification

443 satisfied customers

Journeyman and Master RV technician, Mechanical & Aerospace Engineer. RVIA Technical Consultant

Randall

Randall

RVIA Certification

28,178 satisfied customers

RVDA/RVIA Master Certified Technician with many years experience.

Chris (aka-Moose)

Chris (aka-Moose)

RV Mechanic

2,418 satisfied customers

24 years of experience diagnosing & repairing

Wayne

Wayne

RV Mechanic

2,163 satisfied customers

Work on several type of Rv engine, Trans, brakes

D. Wood

D. Wood

RV Parts Store Owner

205 satisfied customers

Slide Out, Jack & Hitch Specialist

< Previous | Next >

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x