I have a 2005 Dodge Caravan, modified for use for someone in a wheelchair. On two occasions now I have been driving and have lost ALL power, including all dashboard lights, signals, power steering and power brakes. Luckily both times I was able to pull over without much problem (aside from problems steering and having to mash really hard on the brakes). Turned off the motor, restarted, and everything seemed fine. The first time this happened I took it to my mechanic who said he was unable to duplicate the problem, and thus had no idea how to fix it.
The second time this happened (yesterday) was after a severe rainstorm. I can’t remember what the weather was like the first time it happened.
Bad battery or ground cable connections can do this, remove and clean up battery terminals and other ends of cables. Bend cables, looking for brittleness or the feel of wires breaking inside. The next time it happens, shift into neutral,(NOT PARK) and try restarting the engine. You may not need to pull over, Activating the 4 way flasher while you are doing this would be good.
I second oldtimer 11. In case you need more model-specific advice, try allpar.com. They have a discussion site devoted to Chrysler minivans and Pacifica. I found it helpful with my two Town and Country vans over the years.
Since you lost the brakes and steering it seems that the engine had died also. To help pin down the trouble you might try tapping on suspected trouble spots with screwdriver handle while the engine is running. Check the power panel under the hood and the ignition switch areas in particular.