For months I've been wrestling with this problem on my 2002 Caravan. It even sat for the last month and a half completely dead. And then today it started like a champ. When it's dead the instruments don't work, the door lock remote doesn't work and nothing happens when you turn the key in the ignition switch.

I replaced the ECM with a rebuilt unit, replaced the injector harness (which was pretty toasty after 212k miles), replaced the ignition switch and installed a new battery.

Finally I broke down and had it towed to a Chrysler dealer. I was hoping they could put it on their DRS diagnostic and tell me something. When they had it it was in the dead mode. They said they could see the ECM and see that it was okay, but they couldn't see the electrical problem and said there would cost more than the vehicle was worse for them to trace it down.

Today it's running again, but I feel it's unreliable to drive anywhere because there's no telling when it will just go dead again.

Anybody have any ideas about what might be wrong? Or how to figure out what's wrong?

 

It sounds like you may have draw causing the battery to go dead. Does the vehicle make clicking sound?

 

The IPM is a known corrosion magnet causing many electrical problems. Check for connector corrosion or any signs of it on the fuse/relay panel. If it's there, you will likely find loads of it internally.

 

I didn't know what IPM stands for, so I looked it up (thanks Google).
Read more: http://www.ehow.com/how_4521238_repl...#ixzz2cEzH1F1m

It definitely sounds like something I need to look into. I live in the corrosion belt, so with over 200k miles, much of it on heavily salted winter roads corrosion is likely.

The battery, by the way, is new and well charged.

 

Yup, that's what it is. Chrysler would have saved a lot of misery if they had come up with a better way of protecting it.