91 caprice headlight switch gets very hot when plugged in and headlights don't work changed the headlight switch didn't fix the problem

https://www.fixya.com/cars/t25755726-headlight_relay_91_chevy_caprice

and it is a known issue. No fuses, hidden relay.

https://www.impalassforum.com/threads/headlights-dont-work.247307/

https://www.google.com/search?q=1991+chevy+caprice+headlight+not+working

..

check power and ground at the headlight socket for high and low. if you have power and ground there the headlight is no good. if not then you will have to trace back to find the problem, but first I would check the headlight switch after finding out if you don`t have power or ground.

check your fuses,if they are ok ,then check yourdimmer switch, i would also try putting in and trying a set of diferent bulbs.

No headlight relay I know of.
If none of the headlights work, problem could be the dimmer switch or the circuit breaker built into the headlight switch.
You would check for voltage in and out of the switches.

The breaker for the headlights is inside the headlight switch.
You should have a fuse and relay for the horn.
Could be a problem with the wiring harness for the steering column.

it may be the dimmer switch located on the base of the steering colume that is not working on the low beam side.also the headlights themselves may need changing if the low beam filament is burnt out and you didn`t realize one was burnt out then the other one burnt out.if that`s not the case then it could be a bad connection at the plug connector for the low beam or for some reason power is lost between the switch and the headlight.you don`t say if this has day time running lights,if it does then it could be the drl relay that is bad.

Check your headlight fuses, a relay may be on its way out.
Hope this helps.
Cheers

if your running trailor lights and have a plug hangen back there make sure the connections arnt shorting against each other that coul cause the prob

you turn the black harnes clock wise and then the light bulb and harnes shuld come out

The only thing that all of your problems have in common is the light switch and the dash wiring harness. The stereo is linked to the light switch because of it's illumination feature' You need to test the light switch with a test light by probing the wires at it's plug.