94 ranger ignition problem

I’ve replaced the starter, starter relay, key lock cylinder, and starter switch. The truck started fine for about a week after each replacement part is installed. All I get is a click from the relay. I honestly have no clue where to look next.

Try looking just above the passenger side kick panel. There resides the infamous inertia switch relay. They can be very intermittent and a bump can set them off. The relay will cut power to your fuel pump at the most crucial times. I bypassed all of them in the several Ranger’s that I once owned.

Would that cause the motor to not turn over? All I get is a click from the relay when I turn the key

OP: I assume you mean the starter is not turning when you turn on the key?

Yes, that is an electrical problem. Anything from the ignition switch to the starter relay to the starter. or the wiring. Did you check the battery cables for corrosion, both on the contacts and internally?

The molded battery cables can be internally corroded. Replace all of them. Clean all connections while installing the new ones.

When i had the same problem with my 87 i cleaned cable ends and battery posts ,no joy it still would’nt crank
Grabbed my jumper cables and connected one end of the black cable to the negative battery post & the other end to the engine. Now it started right up so i knew the negative cable was shot

This clicks but no crank symptom can be difficult to diagnose b/c it can result from a single high resistance connection somewhere, or multiple semi-high resistance connections spread around the car.

For the starter motor to crank the car it needs these two electrical inputs during attempted cranking.

  • At least 10.5 volts at the B+ post on the starter motor (usually this is powered at all times)
  • At least 10.5 volts on the “start” post on the starter motor (only when the key is in “start”)

Checking those voltages, that’s usually the best way to diagnose what’s wrong. Measure between the terminal on the starter motor and the starter case. If both measure 10.5 volts or above, you are probably looking at a new starter motor. If either measures less, you have to work backwards towards the battery to find out why.

To give you an idea what might be wrong, one time I had this symptom on my Corolla and discovered it was spread out over a slew of gadgets, the battery connections, the ignition switch, the clutch safety switch, and the starter solenoid contacts.