I have a 1998 Dodge 1500 king cab two wheel drive, when I try to crank it by the ignition switch it does nothing but when I by pass the ignition switch and use a jumper wire it will only crank with the ignition switch in a certain place, when I slightly move the ignition switch it shuts off. What could be the problem and how hard is it to fix?
the first thing I would check is your starter relay. You should get power from the yellow wire from the ignition switch that goes to the clutch switch (if you have a manual trans) then it goes to the starter relay. From the starter relay it goes to the neutral safety switch to ground (if you have an automatic trans) the relay gets power from the battery through a pink and black wire from the power distribution box, fuse #2 (30A). Sends the power out on the brown wire that goes to the starter solenoid.
so you would have to see if you have all the correct powers and grounds first, then see what is happening when you turn the ignition switch to start. Is the neutral safety switch grounded in park and neutral? Are you getting your full battery voltage from the yellow wire. The starter fuse should be good or it would never start. The relay could be bad. the switch could be bad, the clutch switch could be bad, the neutral safety switch could be bad, or the starter could be bad.
You have to start from one end and follow it through until you find where the circuit stops.
File comment: 1998 Dodge 1500 king cab starter relay and ignition wiring diagram.