Troubleshooting an RV generator set requires that you think like Sherlock Holmes and ‘deduce’ things so, get your hat, curved pipe (and maybe a beer) and we’ll see what we can do. First, your generator has to have a problem. The first great rule is “If it ain’t broke, don’t fix it”. If it is broke, then we get to play around and scatter parts all over the lawn. Use your senses to help with the problem. Sight, smell, hearing, touching, etc: Troubleshooting is greatly facilitated if you have the service/overhaul manual for your generator. They are available from the manufacturer, a local dealer or on the internet. The second great rule is “Read (and understand) the book”.
The third rule of T-shooting is “determining what type of problem you have”. Ie: Don’t replace the fuel pump if you have forgotten to install the battery. You will troubleshoot differently for operational, mechanical, electrical, or fuel problems. That being said, the majority of T-shooting should be done on a Go/No Go basis. That means picking a point in a system and determining if you have the correct parameter or not.
Lets take a common problem and see if we can troubleshoot it. The engine cranks but won’t start. It ran yesterday at the wilderness campsite, so there is a problem. Remove one spark plug and reconnect the plug to its wire. Crank the genset – SEE sparks?? Yes/No – YES. So it is probably something else. Sniff the spark plug area – SMELL gas?? Yes/No – NO. Aha, a possible fuel problem. Lets go to the middle of the fuel system and test there. Disconnect the fuel pump wire and get a jumper wire and connect it from battery positive to the fuel pump hot wire. Do you get any pumping sounds?? Yes/No — YES, but it’s really NOISY. OK, the pump is probably good so let’s get a gallon jug of gas and connect it to the input side of the fuel pump. Try the jumper wire again. Hey, the pump ran and then got quieter and seemed to run slower. Before you drop that 70 gallon gas tank to change the rubber fuel lines, turn on your ignition switch and see if you have over ¼ tank of fuel -Yes/No — NO. SOF (Statement Of Fact) — RV genset fuel lines go in the top of the fuel tank but stop a few inches (1/4 tank) from the bottom. This lets you run the generator for wilderness camping and still drive back to a service station (RV’s are hard to push). You have just troubleshot for about an hour and finally found it. You have also ADDED to your knowledge of the generator system so all is not lost and I know it won’t happen to you again, don’t I? You will notice that we didn’t disconnect any pressurized fuel lines and test them. If you have to open a pressurized fuel line just make sure an extinguisher is very close and the wife has paid up your insurance policy.
Next week – genset control T-shooting, get your multi-meters ready. — You don’t have one?? Why not?
Generator Jim