Friday, June 2, 2023


RVer wants info for DIY onboard systems diagnostic work

gary-736Hello Gary,
I was wondering if you could recommend a comprehensive technical publication for doing diagnostic work on RV refrigerators, hot water tanks and air-conditioning units? I realize there may be multiple publications involved and also may be specific to type, but I am looking for somewhat more basic tech publications, at least at first. 

I am fairly comfortable technically as I fix helicopters for a living, electrical – AC and DC, engines, general mechanical, hydraulics, pneumatics, etc. However, one thing I’ve learned after 35 years on helicopters – an expert in one field is usually an amateur in other fields. It will just make it easier for me to learn.  I do not have the basic working knowledge needed to foray into the inner workings of these appliances. Last summer our only A/C unit failed and I did find specific publications for it online. After giving everything a good look I discovered – as is so often the case with machinery – an electrical connection to the compressor had cracked and finally broke off after creating enough resistance. A new connector, and we were in business.

Anyway this taught me I needed more information about my coach systems “ready at hand” so I can be prepared for the next possible issue. Any advice would be welcomed. —Mike V.

Hi Mike,
The first thing I would recommend is to contact each supplier manufacturer individually and obtain the owner’s manual or user’s guide for your particular model of refrigerator, water heater, furnace and air conditioner. If possible, also gather the repair manual or shop manual for each device. Of most importance is an accurate wiring diagram or schematic. Oftentimes, like you mentioned, some of these publications can be found online. But most product suppliers do not encourage RV owners to perform their own repairs. Preventive maintenance is another area and I highly encourage RVers to perform as many of the annual maintenance procedures as you can. But troubleshooting and repair is and entirely different animal. I’m sure you’ve found this out working on helicopters all those years.

In some cases, performing repairs requires specific diagnostic testers and equipment not normally found in the typical handyman’s tool kit. Also, specific training may also be required. As an example, reconditioning an absorption refrigerator cooling unit requires not only specific training, but also specialized equipment and hazardous materials training, etc. Same thing for evacuating and recharging a roof air conditioner. But many tasks are performed by RV owners, who, with proper guidance and preparation, can indeed perform their own troubleshooting and repair tactics successfully.

The individual textbooks we use to train professional RV service technicians are available directly from RVIA and can be purchased by anyone at their online store located here.

You can order the complete set, or just the books you want. They are updated periodically, by committee, to keep up with new information and practices. I’ve had the pleasure of serving on that committee for a few years now. The textbooks will certainly go deeper than any other type of book you will find. You may have to apply the info in the textbooks to your specific equipment, but all of the current practices are usually included in each textbook. 

You also might consider enrolling in some of their programs. Anyone can enroll and learn about RV service training from some of the best experts in the country. Or check online for RV maintenance classes.

From the editor: For RV electrical information, we recommend electrical expert Mike Sokol’s excellent book, RV Electrical Safety.

Read more from Gary Bunzer at the See Gary’s videos about RV repair and maintenance.




0 0 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
Traveling Man
5 years ago

There are a number of Troubleshooting Techniques available on the internet these days. Check the manufacture web sites contacting technical support when you need it. Don’t forget to check many of the RV clubs for information. Many of us have had similar issues and are more than willing to lend a hand.

Also, here is another site you will want to save in your favorites:

If nothing else, buy your parts at discounted prices and have a mobile tech perform the install. It can save you a lot of money and time.

Here is but once source for an RV coil pack:

Lifetime warranty and cheaper than any dealer!

5 years ago

Good on line documents here:

Updated by editor (link to manuals):
Thanks, Darrel. 😀 —Diane at

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.