Originally posted by azdave
Let's use some basic logic here. How can a bad battery cause only the lights on the dimmer circuit to be out if the rest of the car has power? If the battery +post was hitting the hood you would have a huge arc welder in action, sparking and smoking. The problem started when you added a harness adapter for the radio so you should follow a schemtaic to the first common point that still has power and then search from there. The working ash tray light is NOT on the dimmer circuit so that doesn't help (except to prove that your battery must be working and that part of the marker light circuit is still operating). I don't have schematics at work (and I'm not downloading them here) so I can't give you exact answers where to start but can you reply back if your marker lights are working? I'm guessing they are since the ash tray light works. You obviously did some damage while hooking up the radio harness. That's the most common cause found when marker lights/dash lights fail. I don't remember there being an individual fuse for just the dimmer lights circuit but until I can review a schematic I can't answer that for sure yet. I'm prety sure the marker lights and dimmer circuit share a common fuse and are fed from a relay under the hood on the left front. BTW, power for the dimmer circuit and marker lights does not go through the stalk switch. The stalk switch provides only a ground trigger for the relay under the hood. If I get a chance to look at my service manuals tonight I post back.