2002 Liberty 3.7 crank won’t start after dying from bad alternator

[Glenn Gibbs]

Hey guys and gals I need some help please. I have an 02 Liberty with the 3.7. I was driving home yesterday and it wouldn’t stay running and shut down at highway speeds. Received codes for crank position sensor and bad alternator. Replaced alternator and after booking battery up to cables have no codes showing on a code reader or on the cluster with the key trick. But it will not start. It will crank however when cranking it goes slow then fast and sounds like something is about to come apart. I have never experienced this before where no codes of any kind but won’t start. I can hear fuel pump kicking on when the key is turned on. Any help would be greatly appreciated

 

[Billwill]

Best to have your battery load tested.

Also check the battery terminals are clean and tight both ends and the two engine grounding straps...at the rear of the heads..are clean and tight both ends.

The Starter or the Solenoid may be failing....check the connections to the Solenoid are good!

I would not trust that your Crank Sensor is good...they do not always post a code...but that should not cause a sluggish crank-over!

A good way to eliminate engine grounding issues is to take a thick cable...such as a Jumper cable with clamps at each end... clamp one end of the thick cable to the Battery Negative terminal and the other end to the Starter Motor casing.
If it now turns over nicely them your engine grounding straps are not doing their job!