Non Ferrari Tech Question

1) Engine quits unexpectedly. Radio loses presets. Therefore 12V is intermittent.

2) Battery tests OK. Therefore bad connection between battery and auto.

Check for poor connection at battery terminals cables (both ends), around alternator + terminal, and around fuse panel.
Since both engine and radio are involved, it won't be in the little wiring, more likely where major cables are.

 

You might want to check and see if there is a ground strap between the engine and the frame, in addition to the ground strap from the battery to the engine, and if such a strap is clean and intact.

And when you say she has had the battery checked, do you mean just a visual inspection ("Gee, it LOOKS all right to me") or has it actually been given a load test? Has the alternator output been checked?

Because of the symptom of the clock losing its preset when the car stalls, this sounds like an electrical problem, rather than fuel. I am assuming that the clock does NOT lose its preset when the engine is normally shut off and restarted.

 

Corroded ground wires at ignition coil bracket or bad PCM.

 

PCM (power train control module) is Dodge talk for the ECU. Clogged fuel filter or as others have said a bad ground somewhere.

 

I would check for a loose ground connection and the battery is not strapped in tight either.

 

Going back to my comment in post #3, if the clock loses its preset when the engine cuts out, but does NOT lose its preset when you normally turn off the ignition switch, then the electrical system pretty much has to be the cause, and it seems likely to me that there is a faulty ground in there somewhere. The same faulty ground could cause the surging symptom and the stalling.

The battery should be OK if the engine restarts after stalling, and the alternator should be OK if it is keeping the battery charged.

A problem in the fuel system would not cause the clock memory to go out.

Edit: I just punched up "Jeep Cherokee" & "ground strap" on google and got all kinds of hits. It's apparently a common problem.

 

I have a 96 Cherokee and I just recently had some battery issues with it that turned out to be cable related. I found that while the cables were alright, my terminals on the battery were toast. I removed them and stripped back a bit of wire and expose clean cable underneath, so I just replaced the terminals with Autozone generics. I also removed the ground strap from the engine and cleaned it with a wire brush on both the strap and the ground location on the block. Problem solved. Hope this helps.