Sneeblii wrote:
but can I bad battery be the cause, or something like a voltage regulator?
Yes it could be just the battery.
In any case, you NEED to have a good charged battery in place and properly connected before you can make a reasonable test on anything else.
Please read the tutorial at the link given in a previous post.
This will allow you to ask better questions.....hopefully......and may answer most of your questions before you even ask them.
THERE IS NO VOLTAGE REGULATOR IN USE......except in your tow vehicle.
When a trailer system is plugged into 110 V (commonly called shore power) OR is being powered off of a generator, there should be an onboard charger that is charging the battery (commonly called a converter).
And I repeat the suggestion that you take it to a service shop and pay them to check it out and explain it to you. That should not cost you more than $100.....if nothing really needs to be fixed.
