My bronco starts every other day

Does it crank and no start or no crank?

No crank and no other power inside the cab except battery light on instrument panel

yes...well the frame to cable connection needs to be cleaned with a coarse wirebrush....follow the black battery cable until it comes to a spot where the lug is bolted to the frame/fender....take that bolt out of there and wirebrush that lug by holding it with a pliers and scrub the spot on the chassis where it will make electrical contact...put them together and with a NEW battery (if yours is five years old) will have full potential and the ignition relay will no longer drop out because it's only seein' 10.5 volts leading to your problem~

Check and clean battery terminals at battery.Check the small ground wire at the battery with the connector for corrosion. Check the ground wire where it bolts to the block.Check the small hot wire that goes to the solenoid on the starter for corrosion or loose connection.

I would start by cleaning battery connection,checking battery cable to if there damaged and to make sure you have a good ground and charge the battery.

Already cleaned up battery terminals and traced positive wire to relay and starter. Will give cleaning the ground a try. Thank you

Check the small wire going to the solenoid at the starter too. These are bad about corroding or spreading out losing contact to start.

with the COLD weather is time for a NEW battery~