Hey I have a 1999 chevrolet blazer 4x4 4 door 4.3 engine. I hit the dome override switch 4 times and my headlights still will not turn off. I replaced the headlight switch and my headlights still wont turn off ,my friend said some thing about a bad relay switch behind the glove box but i have no idea how to get to it any help would be great thanks -Alex-

 

If your truck was originally spec'd for sale in Canada, this trick does not work.

 

It was not spec'd for canada.

 

turn off your truck, hit the parking brake turn on the truck, with the headlights off now check if the switch works. pull the parking brake, and the headlights stay on at all times

 

i have a 99 and it wont work like that either. i did have a 2000 at one time and it worked like that.
it might be a model year issue.
maybe swap in a switch from a 2000 or newer??
or you could just disable the daytime running lights (d.r.l), there is a relay in the power block in the engine bay that you can access and bend the prong back to disable the d.r.l

i have them disabled but still use the auto-head light feature for night driving....couple of options for you

"..........there is a headlamp relay (5 pins) located in the engine compartment or near the steering column, and if you bend over one of the coil pins, #85 or #86, or the normally open contact #87, that will disable the DRL. (#30 and #87a are needed)....."

DRL and AHL "how to" - S-10 Forum