Intermittent Starting Issues

Have you confirmed the brake light switch hasn't loosened up and moved on shaft? I chased a similar issue and the brake switch was the issue. !ight want to do a visual inspection and see is breaker switch moves any. Keep us informed on what you find.

So, I've been thinking. It doesn't make sense that touching the brake pedal is needed to start the truck. I didn't have to do that when the truck was starting normally. It must have started once when I had my foot on the pedal and I just went from there with that belief. To test that theory, I did start the truck today without stepping on the brake. When it doesn't start I get a good click from the underhood solenoid but nothing else. If I jump the posts on that solenoid it starts sometimes but not always. Battery cable is fairly new.

The newer trucks have a brake peddle switch which requires you to stay on brake to start. Didn't know if yours did. I know you know this, but get the battery load tested and inspect all cables for corrosion. It doesn't take much to cause a voltage drop enough to not want to start. If battery is good, sounds more like solenoid is faulty. Battery test free at your local auto parts store and solenoid is cheap.

Good points thanks! It's got to be something like that. The upper solenoid is very inexpensive so I will change that. Battery shows minimal voltage drop when starter does engage. The starter was replaced a couple of years ago. It's a PITA to work on. I bought a cheapy starter off Rock Auto, not the 3x price Motorcraft so maybe that's the problem.

Your local auto parts store can do an on the vehicle starter amp draw for free along with battery load test. Remember I work for a national automotive retailer. If you can find an old timer, like me, the on the vehicle test is actually very accurate, plus it’s free.