Ok. Do you have a digital voltmeter or test light that you can take some measurements with?
Start on the two battery posts. You should see near 12.6 volts if the battery is fully charged. Turn the headlight switch on. We want to make these measurements when everything is dead, but to be safe, leave the headlight switch turned on. By the way, if you bump or wiggle something and the lights come on, look very closely where you're working. Tiny sparks too will be a clue.
If the battery voltage is low, say around 10 - 11 volts, the battery has a dead cell and must be replaced or it is discharged and must be recharged before continuing. If the voltage is around 12.6 volts, move the probes, one at a time, from the battery post to the cable clamp on each post. Both times when you move a probe, you must see the same voltage. If the reading drops when you measure on one of the clamps, that clamp is loose or has corrosion in the connection.
Start with those measurements. If you always read 12 volts, we will need to keep moving the meter probes down the cables to more test points until we find where the voltage drops.
Monday, July 27th, 2020 AT 1:25 PM