headlamps stay on

I have a 99 gmc jimmy 4 wheel drive with 79000 miles. I just replaced the alternator and battery two days ago. I had noticed that my alternator gauge was fluctuating slightly around 14 at idle with no accessories on. Today for some reason my headlamps now stay one as if I left my lights on after turning the truck off. I have to disconnect my battery to shut the lights off. Tail lamps as well are on. Is this related to the alternator or what could this possibly be?
Thanks,

Do the lights stay on when the car is turned off? If so I doubt its the alt, it's more likely a relay.

Do the lights stay on when the car is turned off? If so I doubt its the alt, it's more likely a relay.


Yes the headlamps stay on when the car is off. I have to disconnect the battery to avoid draining it. Relay? Where would it be under dash or hood? I have a Chiltons manual but they are vague. Thanks

the headlight relays are normally located in the fuse panel, there is one under the hood and one in the car, cant remember which has it.

Actually, it may be your switch (thought about this a little more) A good way to test is simply remove the plug off of the back of the light switch and see if it goes out then (also disconnect the dimmer switch) If your lights go out you've found the culprit. As to where the relay for the lights are, I'm gonna have to check my diagrams... Been a while since I've had to look it up.

Any luck?

Thanks for the help fellas. I did end up replacing the switch. I also replaced the relay and put the old one back after replacing the switch. Keep this one for the books!
Thanks!

So in the end it was the switch? Cool..Glad you got it worked out.