1999 Ford Explorer. Many miles. It won’t start in park or neutral. When you turn the key all the dashboard lights come on but there is no turnover at all. No clicking sound either. I’m thinking it’s a bad neutral safety switch. Would that be correct or would there be something else to check. Battery is fine.
That would be one possible correct assumption. But that is not the only thing that comes into play here. It can also be that you are not getting 12vdc to the starter relay and starter solenoid etc…or there is something else going on within the starter circuit…and there are several areas to look into here.
Go under your hood and pull the cover off of your fuse panel… find your starter relay and remove it… You will notice that there are other relays in the panel that are identical to the starter relay you pulled out… If I am not mistaken the horn actually uses the same relay type… Swap those relays and see what you get.
If it still has no effect, you can probe the terminals in the fuse panel to see if you are getting 12vdc to the wire that triggers the starter relay… It will be either terminal 85 or 86 on the relay… see which slot that correlates with using the “map” that is etched into the side or top of the relay. This will test the circuit to see if your ignition switch is providing the relay with a trigger signal of 12vdc (batt voltage)
You can also locate your starter solenoid on the passenger side inner fender area (might be on drivers side, I honestly forget, but i think its on the pass side) under the hood. Once you locate the starter solenoid…you can trigger it yourself with batt voltage on the small terminal that energizes the electromagnet inside the solenoid… If you are able to trigger the solenoid…your starter motor will spring to life immediately…and if your ignition key is on at that time… You will start the engine.
Let us know what you find out when you start messing with the starter relay in the fuse panel. If you have an assistant you can have them repeatedly turning the key into the starter position…and see if you hear the starter relay energizing. If it IS energizing with the key…then do a swap of the relays as energizing is only part of what the starter relay must do… it must also make the connection that energizes the starter solenoid on the inner fender… Sometimes you will find the relay will click and energize yet it unable to provide power out of terminal 87…which goes to the starter solenoid… That means the internal contacts are burned or otherwise screwed up.
Let us know what you find and we can go from there. This is not a difficult thing to diagnose if you have the info you need.