A few months ago I went to start up the truck early in the morning and got...nothing. I think the lights all came on, but it didn't even attempt to crank. Today, I got a repeat and the truck had just been driven prior.

Now with 320K on the original starter, it would be quite easy to point to it as the culprit, but I've dealt with bad starters before and usually I'd get a single click. In this case I get nothing... the lights don't dim, no click, nothing. It's almost as if no power is being delivered. Each time, I've shifted to neutral and it either started, or started shortly after shifting back and forth to neutral and park, then holding the key in crank position for a few seconds. Battery is 2.5 years old and seems to be in good shape when I threw the multimeter on it.

I looked up neutral saftey switch and found this on a jeep forum...."The 4.7, 545RFE does not have a neutral safety switch, it uses a transmission range sensor which is located on top of the valve body."....

So my first plan of attack is to change out the starter relay, then go from there.

Let me know your thoughts, or if you've had this before.

Thanks.

 

If wiggling the shifter will get it to start, think it would check for slop in the shift linkage, and also check adjustment. Replace the starter relay, as it is a cheap and easy job, but, if it still gives you issues, probably time to have a hard look at the range sensor.

 

I was waiting for it to happen again and it did today. I shifted into neutral and still nothing. Popped the hood and replaced the starter relay. Cranked up immediately. Tossed the old relay. Lets see if that does the trick. That would be the second bad relay (first was fuel pump) in as many months.