I only have a '99 service manual for vans, but by that year, it appears they changed the style of ignition switch so you're going to know more about it than I will. The radio and signal flasher are on the "Run / Accessory" circuit. The cigarette lighter is on that circuit too so you should find it inoperative at the same time as the radio. The power windows, along with the anti-lock brake controller, ac / heater controls, rear window defogger, rear heater, and air bag controller are on a different circuit leaving the switch. If these two circuits go dead at different times, that would point to burned switch contacts, but there are two totally separate switches physically linked together. If both circuits always go dead at the same time, that would point to something they have in common, and that's the common feed wire. That magic wire is a 12 gauge, pink with a black stripe. Current leaves fuse 12, a 40 amp under the hood. The feed to that fuse is the same as that which feeds a different 40 amp fuse for the starter relay through a different part of the ignition switch, so we know the circuit is good to that point.
From the fuse, current goes directly to the ignition switch, (that pink / black wire). There is only one connector shown in between, presumably the bulkhead connector which probably isn't really bolted to the firewall. They've moved them inboard on cars back in the mid '90s. That connector would be a good place to poke a test probe to monitor the circuit for loss of voltage. If you have to go on further to the ignition switch, pull out the tilt lever, then there are two screws in the bottom half of the steering column cover. It unsnaps from the upper half of the cover. I think that's as far as you have to go to access the switch wires.
That will give you three test points to start from; the switch, the fuse, and the bulkhead connector in between. To find fuse 12, you'll see two rows of maxi-fuses under the hood. One row is exactly in the center of the box. Start counting from the large bolted-in 140 amp fuse. Next to it is fuse number 16. The fifth fuse away from the 140 amp is the one you want. Depending on the style of fuse, you might be able to pop a clear cover off to allow you to connect a clip lead to it and your probe. If you find the voltage disappears at that fuse, suspect a loose rivet on the buss bar underneath that all of the fuses in that row are attached to. I've read about that a few times but have never run into that myself. I suspect a loose rivet can be shined up and soldered to solve a problem there.
As a suggestion, you might consider leaving the radio on, (I prefer AM talk radio), while you're poking around the test points. That will provide a clue if it quits when you disturb something.
Friday, September 10th, 2010 AT 4:56 AM