The long skinny black box by the battery.
It has fuses and relays in it.
You can open it on one end, and then take the cover off.
It has a map of all the relays and fuses inside the cover.
You can trade the positions of two relays that have the same number on them, and see if the problem is fixed or if it moves with the relay.
If the problem moves with a relay, then that relay is bad.
If the problem stays, and the relay you used is known to work, then it isn't a relay problem.
Make sure to replace the cover as soon as you are through, so water doesn't get into the box.