1. Batteries. Typically there are both engine battery(s), and coach battery(s). Make sure they have been replaced relatively recently,
IMHO, don't worry too much about the battery condition during the purchase. The reasoning is that you want good batteries when camping and the only way to insure the batteries are good and dependable is to replace them with new ones. (I knocked the price of my motorhome down $500 right off since the older batteries were likely weak and I'd be replacing them myself soon. The old ones, including the supposedly newer battery didn't last 3 months. $200ish later I had three new batteries onboard)
or at least that the coach batteries have been serviced. RV's are often plugged in and overcharged, which burns off the water/electrolyte from the coach batteries (typically the engine battery is sealed).
Engine batteries can be sealed or non sealed. Look and see what you have onboard.
Overcharge burns off the water, not the acid. That's why you add water to a low battery, not acid. Once the level drops below the top of the plates, it starts cutting into the life and charge condition of the battery.
As for having batteries serviced: On non-sealed batteries, learn to pull the caps off the battery and fill them yourself unless you want to fork out a fortune for new batteries or five fortunes to have someone else add a little water from time to time. Distilled water only. It's a dirt simple thing to do and the RV shops want $150+/hr labor to do it and they'll likely hit you up with 2 hours of labor to do a 3 minute job with a cup of water that is hopefully distilled.
3. Generators often do not get used for weeks/months at a time. As a result, they often do not start easily, nor run well. Make sure this one runs well. Generators in RVs are often difficult to access, which makes maintenance expensive.
A running genset engine just means the engine works, nothing else. Take a voltmeter with you and check the output voltage. If your voltmeter does frequency, check the frequency as well. Do this while the generator is
under a load load such as running the air conditioner and microwave. It should stay close to 60hz and voltage should be stable at 120VAC plus/minus 10%. If the genset is not under load, you can't tell what the genset is actually putting out reliably.
4. Electric plug in cables. Many RV campsites offer the ability to plug into electric service. There are several different cable sizes and connector types for 50, 30, or 15 Amp service. Ideally, it would be wired and have connectors to support all of these... having said that... 50A service is likely to be overkill in all but the largest RVs. 15A service can be underwhelming, especially if the coach A/Cs are being run in the summer.
Campgrounds have 50/30/15 and sometimes 20A services. (20A is a standard 15A 3 prong plug you find on the end of a generic extension cord) 15A is available anywhere electric is available. Most have 30A nowadays. More and more have 50A since that's becoming common with the huge monster motorcoaches. Every campground I've been to with power has 15A. If there is 30A, there is also 15A connection at the site. If there's a 50A, it usually has a 30A and 15A connector as well. That's not always the case however that's how the generic power pedestal is setup.
On a RV or motorhome there will be one cable, not multiple power cables attached to the vehicle. Most Class C's use 30A connectors until you get into the monster C's that use 50A which are all fairly new still. Since you're almost certainly looking at a 30A connector on the one you're looking at, in reality all you need is a short 30A to 15A cable or plug block to take care of any campground power plug problem you'll ever encounter. That plug conversion piece will put you back a whole whopping $2.50 assuming the place you buy it from rips you off. (I would mail you my spare however postage would cost 50 cents less than a new one would) Don't worry about the 30A to 50A connector unless you just want to carry around extra junk you'll never likely use. If you're plugged into 15A, the AC won't run more than about 5-10 minutes before the pedestal breaker pops since AC units typically pull 18-25A.
BTW, 50A on a motorhome is actually two 25A circuits, not 50A. It takes the two phase 240VAC wiring just like for your home clothes dryer then splits off one phase as 120VAC at 25A and the other phase as the same 120VAC at 25A. Onboard, the wiring is setup as two independent circuits that are not directly connected to each other and runs that through the motorhome as needed. If you look with an oscilliscope, those circuits are 180 degrees out of phase.
A few big things:
Check all the onboard systems. Water heater, air conditioner, furnace, water pump, lights, converter, etc. However just because something isn't working properly, don't immediately write the motorhome off. Consider what the problem is and whether it's fixable easily and cheaply or not or if there's a list of other fixes growing. I didn't get fanatical about broken stuff while generally knowing what I was looking at and using common sense while buying. Three batteries, a water heater ignition board, seized water pump, installing a holding tank heater box and a few other minor things saved me over $4000 even after fixing those things for about $500 total over the going price for a similar motorhome at RV shops.
Slides: Slides are the big thing everyone is pushing nowadays in today's bigger is always unconditionally better mindset. They do tend to develop leaks over time which means seal replacement or sometimes major work when the hardware bends..especially if there is a drive screw failure. Also a lot of small campgrounds have sites too small to extend the slides without hitting trees and such. If you're going to be going somewhere other than huge motorcoach resorts all the time, make sure you can use your onboard systems such as the kitchen, bathroom, sleeping areas, etc with the slides pulled in. Keeping the slides in allows you to stealth camp without drawing attention to yourself. In addition to width, length will keep you out of campgrounds sometimes. I've been to several places that if you're over 30 feet, you simply can't fit into the site.
Refrigerator. These are absorption fridges (no compressor) so it takes 4-8 hours to reach running temperature. The cooling fins and ice box cooling surfaces inside will get fairly cool after about 1-2 hours of run time. Verify the fridge works on AC and propane. Also look inside the outer access panel. If you see a yellow stubstance that looks a lot like sulphur in color below the burner box, the fridge is dead and a big fire hazard even if it cools a bit with that yellow stuff there. The only fix is to replace the cooling unit for $1000 or a new fridge for $1500 plus labor if you don't do your own work. (BTDT)
Tires: Age, not wear kills most RV/motorhome tires. Check the tires for dry rot. Forget about tread depth because that's not important at all unless the treads are worn. I've seen many brand new tread depths and severe dry rot that have caused no end of grief. You want to look for any small cracks on the sidewalls AND down between the treads. It's a PITA to check dual rear tires however it's something that must be done. I've seen the results of several campers and motorhomes that had dry rotted tires go KABLOOEY at speed. The damage is pretty substantial in the wheel wells. Also if there happens to be onboard systems wiring down in the wheel well area (and that's very common in designs) all that wiring will be torn out when the tire delaminates. (Six tires will run you at least $1000 on a normal size motorhome and lots more if it's a monster machine)
Check for water damage. Soft walls or floors indicate water damage. Pull a fixture out of the ceiling and walls and stick your finger in there and check for water rot. Under cabinets there is often minor water damage caused by a drain pipe or valve, or water tank hose that came loose in the past that is in reality a non event. Determine the cause and extent of damage.
Awnings are spendy and very useful. Roll it out and check for rips and that the spring rolls them up properly. Tiny holes at the top near the attach point on the motorhome are common after about 10 years. If it's just small holes and no rips, there's plenty of repair tape available to make those holes waterproof again.
Don't be afraid to turn your own wrenches. RV shops can often make aircraft maintenance shops look like third rate amateurs when it comes to cleaning out your bank account. Most onboard hardware can be fixed with a trip to the local hardware store. (1/2 inch schedule 40 PVC is 1/2 inch schedule 40 PVC. The difference is that the hardware store sells it for $3 for 10 feet and the RV shop near here sells it for $11 a foot)
All that said: Just find something in reasonable condition and go have fun camping. Don't overthink it or worry too much. Don't carry a lot of unnecessary junk because you don't need it. Get use to dumping your own poop. Above all else, keep a good attitude and sense of humor. When something doesn't go precisely as planned, it's just part of the adventure.
Peace out. Happy camping.
<--- Fulltimer (Three years so far and going on winter #4 in Colorado)
