Have a very frustrating problem with a 96 850 sedan. The headlights and running lights stay on after the ignition is turned off and the light switch is on off. I thought it was a defective headlight relay and replaced it with an original part, but the problem continued. I tried unplugging the headlight switch, ignition switch, fog light relay and the blinker/flasher switch, but the headlights stayed on!!! Unplugging the main headlight relay turned off the headlights, but the running lights still stayed on. The only action that turns all the lights off is unhooking the batthery! HELP, I'm really stymied and frustrated!

 

Just a WAG but i would suspect the electrical part of the ignition switch.. Someone with access to a schematic is going to have to trace it down..

 

My guess would be that you have a short somewhere. Something like a bare wire that is making a contact. That's crazy, especially if they are on with the switch unplugged.

 

I had replaced the electrical part of the ignition switch a while ago, so its relatively new. However, the lights stay on even with the electrical part of the switch comletely unplugged ! I have unpluged every single relay in the car including the ones under the dash behind the firewall, but the dggone lights won't turn off. I am guessing it has to be short in the wires going out of the light switch, but that's going to be a bear to trace, since they are routed through the firewall into the main fuse box area along with a million other wires...
Any other suggestions would he helpful

 

I've heard of people having shorts along the edges of the front bumper.

 

OK, you guys convinced me... I would look for pinched wires in the steering column area to start with..

Also if you can isolate it to a fused circuit (i.e. if the lights go out when you pull a specific fuse #?) then that would help constrain it to a local area on the car.

 

Problem solved...Pulling the headlight relay made the headlights go off, but not the running lights...the harness from the main light switch went into the dash, thru the firewall, into the main power distribution box under the left rear of hood, where it went to relays, then to fuses, and on to the lights. Pulling the fuses made the lights go out, so I figured the short was between the main light swictch and the power dist. box. I took off the top dash cover (a grueling task!) removed the instrument cluster, and discovered that some genius who had worked on the car before, had tucked the harness between the cluster and the sharp metal edge of the interior dash frame, which eventually sawed thru the insulation and grounded the wires from the switch... I freed the harness, taped off each bare wire, lights are off, and problem solved! Thanks for the suggestions everyone!

 

Wow! Glad you found it but that's nuts. It probably would have taken me weeks to find that.

 

Good catch!! Will call you for my next electrical problem; you're now the expert..

 

I have the same problem. The headlights and running lights don't go off. It is somewhat intermittant, but more intermittant than not. Car is "new to me", so it is possible that someone has been under the dash, I'll give that a try. In my search I noticed that someone on the UK board had the same problem posted, no significant responses. I think I will try banging on the dash first.

 

Thought I would add this. Directional lights work when ignition is on and car is not being driven, do not work when being driven.