Turn on my headlight on my 89 comanche my radio shuts off and and my turn signal is on

SOURCE: rear brake light doesn't work when headlights on

If you take the tail light assembly off and take the bulb out, you'll see three metal contacts on the tail light assembly.  Pry them up slightly and slide a small, folded piece of aluminum foil underneath it.  
Replace the bulb and try to reproduce the problem.  I found this fix online and did it to both sides of my car.. no problems since

SOURCE: headlights and dash light dont work

You would have to check and see if you are getting any power out of the light switch. There is a seperate wire for the headlights and the dash lights.

SOURCE: 2001 jeep grand cherokee lights

The problem is with the connection from the light bulb holder to the socket that the bulb and holder go into. I believe on my 01 JGC it was the top light that was going out when i applied the brakes with the lights on. If you remove the light bulb holder in the tail light assembly and look at the area that the bulb and holder came from either the metal that makes contact with the holder for the bulb is depressed, or in my case it was cracked. You can use a small flat scewdriver to lift the metal in the tail light assembly, or as i did, i just put some tin foil on top of the metal, then reinstalled the bulb and holder ontop of the tin foil (this makes the elec. connection). seems like a rigged up solution, but made sense to me, and worked!

SOURCE: Dashboard lights and tail lights don't work

Check the TAILGHT FUSE. GM's unusual way of letting you know there is something wrong. Otherwise how often do you check your tailight operation. Only by another driver telling you, your tailights aren't working, would you know. Hope this helps.

SOURCE: 98 jeep wrangler headlights wont turn on

I would check your headlight relay switch that is located in your steering colum