Daytime running lights and headlights dont work and horn blows randomly

check the trailer harness if your truck came with trailer package those harnesses are known to go defective. do daytime running lights work?

A faulty daytime running light relay can cause this. I've seen cars parked and lights and horn start to go on and off. Like everything else as time goes by by drl's daytime running light relay and modules do go and need replaced.

this is the main light diagram Low beam this is the diagram for the daytime running lights. hope this helps... there have bee a few reported problems with the radio blowing and then the light go out if the radio is fine it could be a fault with the LED control relay if this blows it can blow the 10amp fuse for the lights. you need to get the right relay as there are two types touch and none touch. tast one this is were all the units are

light sensor is going bad..or bad light switch. Sensor are usually located in center of dash facing the windshield. Clean it first and see it that helps.

There is a microprocessor in the instrument cluster that grounds the DRL relay - do you know if the relay has power from the headlight fuses and is being grounded by the processor ?

The problem with HID lights is that they require 12 volts or more to work. Daytime running lights on require 6-9 volts from the module. So when the original lights are replaced, the daytime running lights will not supply enough voltage to the HID ballasts to turn them on. The result? No Daytime Running lights. Another alternative is to purchase LED strips and place them around your headlights with a fused accessory power from the ignition switch. When the car is on the strips light up and you have Daytime Running Lights!

The blinking light is telling you that you have a headlight out, if you look the service light should be coming on when the light stops blinking.
Replace the head light and all should be fine.

Daytime runnning lights mean that the headlights are on in the daytime. On my 2005 MAlibu I can turn these of by truning the headlight swithc from auto to off.

Sounds like you have a problem in your headlight switch. As far as them staying on sometimes when you shut the car off are you referring to daytime running lamps or the regular headlights? If it's daytime running lamps that like to stay on and your headlights do not like to turn on then there could be a combination of headlight switch and daytime running lamp relay.

It is possible the relay gets the signal from the headlight switch as well, since they generally turn off when you turn your headlights on.

Well...lets start with the obvious. Check fuses and NEVER piggyback any stereo or security stuff into their fuses...you dont want the lights to shut down during a night drive!!
Check under the hood for a relay center...also has some fuses there as well.

The Daytime Running Lamps are a "straight through wiring configuration". Doubt it even goes through a headlight switch at all.
But the regular lights do.
Unless you've worked on the front of the car and forgot to plug the headlights back in, do this...
Turn the light switch on...looking at the instrument cluster , can you make the high-beam-indicator light come on?
As you rotate the headlight switch knob...does the instrument panel lights brighten or dim? You probably have a faulty headlight switch...auto stores have them...they simply plug in.