Question: My 120-volt power does not work when the generator is working. What could be causing this problem?
Answer: I am going to take your question to mean that your generator is not providing power to your 120 volt appliances. If so, several things need to be checked.
First, begin with your generator. If you have an older unit you may have to connect your power cord to the generator.
Then, check to make sure that the generator circuit breaker(s) have not tripped. If they are tripped, reset them by turning them off and then back on again. When resetting the breaker(s), feel to make sure that the breaker(s) are good, over time they do tend to fail. If there is little resistance when reseting the breaker(s), then replace them.
Next check for a tripped GFI outlet and reset it also.
Go to your A/C power distribution panel and reset all of the breakers in that box. Remember to feel for weak breakers and replace any that seem too easy to reset or that will not fully reset.
Lastly, since you have a generator then you also have a power transfer switch that may have gone bad and is stuck in the shore power position.
If you have a trailer, then another possibility is a bad converter.
If you want to further diagnose the problem, read on.
Huge caution: Never work on a converter while it is connected to live power unless you are skilled in electrical trouble shooting. The few dollars you save may cost you an injury or your life.
However, if you feel comfortable working on the converter, you can check to make sure that all of the converter connections good and tight and that there are no burned wires.
Do you have a good battery connected to the converter? I read somewhere that a bad battery can cause similar problems.
Also try resetting all circuit breakers in the converter and make sure that they are good.
Power Transfer Switch:
Huge caution: Never work on a power transfer switch while it is connected to live power unless you are skilled in electrical trouble shooting. The few dollars you save may cost you an injury or your life.
However, if you feel comfortable working on the power transfer switch, you can check the contacts to make sure that they are operating properly and that the contacts are not pitted or welded shut.
If you still do not have power at your outlets then you will need to take your RV to a professional to resolve your power issue.
Please let us know how you resolve your issue and the cause, so others can learn from your experience.