I recently bought an 04 aviator that occasionally (every couple weeks) wont start. Normally everything works fine but when it acts up it will just click when trying to start. It has a brand new battery and all the lights and dash lights work fine and do not dim when trying to start. I honestly think its the starter or solenoid. From what I can find on google, replacing the starter seems to be an aggravating task. My question is, Is there a solenoid on the firewall and also on the starter or just the one on the starter? And how would I test each to see which one would be the problem.