Jeep sat for several months. Put fresh gas in and was able to crank, run and drive for a few days then it wouldn't crank. Just clicked when turning over. I have replaced the starter and the battery within the last week or so. All my battery/starter wiring has been updated (previously) with larger gauge solid copper wire that is tinned, lugged and heat shrinked. No corrosion at any connection points. When attempting to crank I get a rapid clicking noise. Took the new battery to the parts store and they tested it and said it was good. Is it possible that the new starter is already bad or was bad out of the box? I tried jump starting with another vehicle and get the same rapid clicking. Not sure what to do next. Any insight and/or help would be greatly appreciated.

UPDATE: Took both the new starter and old starter to the parts store and both tested good. So, good battery and good starter, but still get rapid clicking when trying to start. No corrosion at any connection point. At a loss.

UPDATE: Switched the horn relay and the starter relay and the horn works with both relays, but still just get rapid clicking when trying to crank with either relay.