I just replaced the starter and solenoid on my 99 ranger and it started right up. Drove it for the rest of day and it started up fine Everytime. Once I went to leave work that night it wouldn't start. Everything would turn on but there was nothing from the ignition, no clicks or anything. The battery is good, the starter relay is good, there's power getting to the solenoid. What else could be the problem? Any help will be appreciated. It's 99 4cylinder automatic 2wd.

 

Welcome to the forum

First lets talk a "solenoid"
A solenoid MOVES something, "starter solenoid" is on the starter motor and it MOVES the starter motors gear out to make contact with the ring gear on the flex plate.

A "relay" sends electrical power to a device when relay is activated.

On your 1999 Ranger when you turn the key to START 12volts is sent thru FUSE #24 in cab fuse box, to the Transmissions Ranger sensor(DTR), if transmission is ALL THE WAY in PARK, or Neutral, then that 12volts goes to engine fuse box and activates the STARTER RELAY in that fuse box.

STARTER RELAY then sends 12volts to the starter solenoid(on starter motor), when it MOVES it also closes two contacts which connect BATTERY POSITIVE CABLE to starter motors brushes and starter motor starts to spin, after gear was pushed out.

In 1999 there should be a smaller wire on the starter solenoid, yellow/blue stripe wire, thats the wire from the STARTER RELAY in the engine fuse box, it should have 12volts when key is turned to START.

If it does, you WILL hear the Solenoid "CLICK" pushing the gear out, and if starter motor does not come on the starter motor is bad, or not connected to Battery
If Solenoid is not "CLICKING" and wire has 12volts then new starter is bad, it happens

If you don't hear the solenoid "CLICK" then transmission might not be all the way in PARK, so try NEUTRAL to start engine.

Or check FUSE #24 could be blown

START RELAY in the engine fuse box can be used as part of a Ford Anti-theft system
The Key sends 12volts to activate this relay, BUT a relay also needs to be GROUNDED to activate, so Ford hooked the GROUND wire for this relay to the anti-theft system, if alarm was tripped starter relay was left ungrounded so No Start


About "new" parts
New used to mean "tested and working"
New now means "you test it and we will replace it, if it doesn't work"

Quality control is LABOR, and labor is expensive now a days, yes even in China, lol.
One of the reasons Motorcraft parts are so expensive is because Ford still requires Quality Control for all its parts, it's worth it to them to not have a part not work or fail early when assembling new vehicles

 

And rebuilt can mean degreased and spray painted. Check the above but i wouldn't be surprised if your new starter is a dud. (auto parts stores will test them for free - have them test it several times in a row - get it nice n warm as if the engine were cooking it. Most starters and motors in general hate heat and can open up/short when heated but work fine when cold)

 

After testing the starter at local auto parts store it tester good. I cleaned the ground of grease and dirt before putting it back on and still nothing. What's next, ignition problem?

 

Check out the power cable to the starter. Check the power voltage at the starter when off and when trying to start (on my 91, should be 12 off, 8-9V when starting). Also, check the control voltage at the starter when off and when trying to start (0, or near enough and then 12V or so when starting). Check the voltage between the starter and the ground of the battery, same conditions.
I had the same problem, even got to the point of buying a new (not rebuilt) starter, with similar results. the power cable had a break where it mounts to the battery, and a foot of corrosion in the cable. I did the above and saw 12V drop across the cable when I tried to start it. Should be a couple of volts, max.