Contour Enthusiasts Group Archives Forums General Troubleshooting Light Electrical Problem

I'm having a weird electrical problem on my 99 Mercury Mystique LS Sport, Zetec auto. I've tried searching but never found a problem like mine. When the I turn the key to the RUN position the lights turn on. The headlight switch is in the off position. Everything seems to work, can turn highbeams on and off, fog lights on and off, hazards and turn signals. Also without the key in the ignition and if you turn the headlight switch, it like having the key in the RUN position. I can turn the heater on, move the windows up and down. The radio will not turn on though. If I turn the ignition off while the headlight switch in on, the car will keep running until I turn the headlights off. Right now I've unplugged the headlight switch and the turn signal switch but the lights still turn on when you put it in the RUN position. I've pulled the DRL and headlight relays but had no effect other than the headlights not turning on while the instrument panel is still lit up. Any help is much appreciated.

This is a tough one. You have a short between the headlamp switch wiring and the ignition switch wiring.

Check the wiring under the Passenger Compartment Fuse box as well as te wiring under the Power Distribution Box next to the battery. Especially the wiring for the fuses and relays for the headlamp switch and ignition switch.

I've found when you disconnect the dimmer switch, the light switch acts normal again but the lights are still on. I took the fuse box apart and everything looks fine. I don't know what to do?

The light switch doesn't function like the ignition switch anymore. It just turns on the headlights and foglights. It won't however turn the parklights off, and the dash lights.

Just remembered the correct term for it. "Crossfeed" (not short; thanks, Big Jim). Need to get a wiring diagram and look for where there might be a crossfeed. Look at where there is an "always hot" wire (like clock, cigar lighter....). Once again, need to check ignition switch wiring and headlamp switch wiring.

Edit. Check wiring for sockets in Passenger Compartment Fuse Box (left of steering column under the dash).

Fuse 27 Cigar lighter (orange/yellow wire and red wire), Fuse 34 Clock (orange/yellow wire and red wire), Fuse 30 Ignition Switch (green wire and violet/yellow wire)

Some pictures and help from SetiRich
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=1056473&page=&view=&sb=5&o=&fpart=all&vc=1

The crossfeed is somewhere in the interior lighting circuit (fuse 31) after the light switch. It would be a switched source on the ignition run circuit that is shorted the interior lighting. I've ruled out the door locks, power windows, cigar lighter, instrument cluster, heater motor. Maybe I'll just start pulling fuses. It's probally something simple but I can't find it yet. I've been looking at the wiring diagrams in the Haynes manual and the CD shop manual.

I've found that if I have the e-brake all the way pulled up. It has to be the last click the dash lights go out. So would I have a pinched wire under the console?