I have an 06 F150 Lariat with 33,000 and the 4 wheel drive is intermitting. I'm hoping it's just a loose connection somewhere but didn't know which harness would be the best place to start? Thanks.

 

Welcome to FTE!!!

Your problem is very common and resolved by replacing your IWE solenoid. It is behind the battery on the firewall. '04 - '06 had a tendency to get water inside the solenoid from the windsheild cowl. A newly redisgned solenoid is available at your dealer for about $30.

It is easily replaced. New Part number is 6L3Z-9E441-A