My 2000 Ford expedition Eddie Bauer edition has an undiagnosed electrical
issue. It eats batteries and can't be counted on to start once you stop at your
destination. Two mechanics have failed to find the electrical issue. What is a
realistic cost to re-wire or replace the electrical system?
Does yours have the ECM controlled alternator, or any form of ECM controlled battery management? As to costs to replace wiring, I would get a proper diagnosis of the problem before spending money to just replace all wiring. There is a ton of various harnesses, grounds, modules, and so on the cost of which to replace would very likely exceed the value of the vehicle. In the meantime, if you're actually killing batteries (and not just draining them) look at the voltage regulator for spikes.