2 components to start with

Ignition switch, located on top of the steering column
Solenoid, located under the hood, the one for my 2000 is on the firewall, I had a 97 I think it was on the passenger side near the battery

Both are fairly inexpensive parts, If they haven't been changed, just change both of them.

 

I have extra solenoid (new) some where in garage try to find and change it next day or so and I let u know If it is ignition switch I should replace(is there a way to know if is the ignition switch).ty

 

the ignition switch is a mechanical switch, that energizes from the movement of the key. When activated it sends power to the small pole on the solenoid, which activates the starter. You can use your multimeter to see where the problem is. The switch is only 20 bucks at your local store, its usually wise to replace it by the time you remove it to do much testing.

 

Sorry my brain is not working these days and I remembered the switch I look at and let u know.ty

 

I did change the solenoid and ignition switch too.It starts smooth and better than before.The place that you screw the plug on switch came out ,when I took it.It could be the problem,I hope.ty

 

It did it again this morning.It wouldn't start but this time after 3 or 4 times at Neutral,it did start.

 

Is this only when it's hot, as in recently driven that it acts up? First things first though, you need to crawl under there when it's acting up and check the battery+, ground, and switched 12v to the solenoid.... while somebody else holds the key in the start position. If you're getting power to the solenoid and everything else checks out then it's the starter, regardless of Advance testing it. They just bench tested it, not get it heated up and tested.

If you're missing power or ground somewhere then you need to go upstream to find the last spot you have power.

 

It does it both hot and cold,sometime coming out of store(10 to 20 m9ntes).Lately in the morning first start and after 30 to 40 minutes it starts.

 

Gotta crawl under and start some diag

 

I should do the test under the truck when the truck can't start and acting up or can I do that now (truck starts now)?
Can I do the under truck testing alone ,by myself? ty

 

Unless you make some crazy long wire extension you'll have to be under the truck while having somebody else turn the key and hold it in the "start" position. You can only diagnose when it's not working.

 

Intermittent failures like this are the worst to pin down, but I suspect a questionable cable playing a part in this scenario. While it is true that switches and relays DO fail, the timeframe is consistent with load. Plus, the ignition switch is only passing a few amps at most, enough to trigger the various key-switched relays and the fender mounted starter relay (1A at most). Keep in mind that these cables are almost 20 years old and corrosion never sleeps.

If the starter is refusing to crank, have you tried hot wiring the starter relay on the firewall for diagnostics? That would reduce the number of variables to starter, battery, relay and cables.

My starter is original and when it was misbehaving in the same manner, it benefitted greatly from having fresh cabled with properly soldered lug terminals. Ford did things rather a**backwards and it can help to de-clutter the mess of cables down to a more logical number. Rerouting the Battery positive cable from the starter relay to the alternator fuse can boost charging by 0.5v. I did this on my DIY'ed fuse block to eliminate one cable, then added a short bus bar to feed the Main Fuse. Works fantastically.

 

I will (hopefully t goes down when I am home).

 

I just go ahead and change the cables and terminals ,Could you tell me whats the good set of terminal and where should I get the cables from(I can make the cables)?

 

I use Marine Battery Terminals on every vehicle and get cable from a local welding supply store (DeLille Oxygen) along with the copper lugs. It's far cheaper that way, just be sure to solder them yourself. Google Aaron Cake's RX7 Grounding article for a how-to and follow it to the letter. It just works.