How to tell
Where do I test to see if truck is charging the fifth wheel batteries? Can I tell at the battery connections? I know I have a controller, but not sure how that is wired in the system. While driving a ...
Forum Discussion
Easy, but you need a voltmeter. Fords have a relay so they only power the 7-pin when engine (or ignition?) is on. So plug in the 7-pin with truck off. See trailer battery voltage at 12.x. Now turn on truck. Trailer battery voltage should go to near same as truck voltage-- 14ish.