Will not start how intermittently ? The engine won't turn over or engine does turn but won't start . Starter relay , lose connection . Checking power an grounds would be the first place to start , voltage drop test the main electrical circuits .
Voltage Drop Testing the Starter
The starter circuit control is achieved by the starter motor relay ! It is located in the under hood fuse/ relay box or as Chrysler calls it ,integrated power module ! If you pull out the relay an look on the bottom where the pins stick out you will see four sets of numbers .30,87 an 85,86 ! 30 is B+ voltage . 87 is to the starter solenoid . If you jumped those two spots where the relay plugs into the starter would crank the engine over . The last two 85 an 86 are the control side .If you checked with a volt meter where 86 plugged into ,with key on it would show B+ voltage . The last pin is from the PCM - engine computer . When turning the key to start a signal is sent to the PCM to let it know crank has been requested , in return the PCM supplies a ground to pin 85 energizing the starter motor relay sending B+ voltage to the starter motor cranking over the engine . Here is another video on test from the relay base (where relay plugs into ) This is for a horn circuit but same thing .
VEHICLE RELAYS Testing from the relay base The relay could be going bad , you never know .Replacing the relay mite not be a bad idea . Good luck , hope this helps !