Bizarre Electrical Issue With 97 3.8 V6 Marker Lights/headlights, Switch & Radio

Kavin Lennon

New Member
Oct 1, 2016
So it started when I plugged a usb charger into my aftermarket deck in my car... I heard a weird whirring noise accompanied by a loss of my back light illumination and audio output to my deck. Basically rendering it useless. I tore into it and checked the deck directly with the battery & it powers up and functions fine... Now, it was around this time that I realized my marker lights weren't functioning properly with the headlight switch (I'm assuming these issues are interconnected) I've replaced the headlight switch, checked all the fuses in both the hood panel and the panel on the floorboard of the car, I've pulled the pigtails for the front and rear lights, license plate lights, etc. Also, the switch itself works fine, I checked it against my 89 f150, and it functions properly in that vehicle. (Same model of switch) Note: the switch itself might be fine, but the way it is function ing in the Stang isn't. if I pull it out one click (where only the marker lights should come on) nothing happens. Pull it out half way between the marker and full headlights and my marker lights come on. Pull it out all the way and only my headlights work. (No marker lights or interior dash lights) I'm not sure what else to check. I dont know if I'm missing something but any help would be greatly appreciated.
  • Sponsors (?)


SN Certified Technician
Aug 14, 2009
Houston Texas
This is one of the problems with the forums. IE that people do not always update their threads with what was learned. In this case the OP joined. Open a thread. Checked it the next day only to never be heard from again.

For anybody else reading this, here's some information regarding what was found.

Light issues

TLDR; short version. Blown fuse.