My 2004 Trailblazer air cond does not work on 1,2,3,4,on 5 it starts and then my Service Four Wheel Drive, ABS and Brake Light come on. If I turn the air off the lights will go off in about a minute.

First you need to have EBCM - electronic brake control module check for DTC'S - diagnostic trouble code's . If the light is on there is a code stored . I think most part stores can do this and for free . After you find out what code is stored , looking up that code in service repair information for diagnostic trouble shooting chart would be next step . There are a few codes too.
DTC C0035 or C0040
DTC C0045 or C0050
DTC C0110
DTC C0131
DTC C0161
DTC C0186
DTC C0196
DTC C0201
DTC C0240
DTC C0241 or P0856
DTC C0244 or P1689
DTC C0245
DTC C0283
DTC C0287
DTC C0290 or C0292
DTC C0455
DTC C0550
DTC C0558

Find the code do the diagnostic's , fix the problem , wiring issue's , a sensor , bad module ,what ever it is . The light will go out then . Here is a sample of code discription .
• DTC C0035 Left Front Wheel Speed Sensor Circuit
• DTC C0040 Right Front Wheel Speed Sensor Circuit

Have you had the vehicle checked for DTC'S - diagnostic trouble codes ? I would start there first . Battery , charging system all good ? What computer , the ABS has a control module all to it self . The Air con has a relay in the under hood fuse box controlled by the PCM / engine computer . If there is a problem with ABS , The EBCM - electronic brake control module will turn on ABS and the red brake light .
A low voltage condition could cause this problem , but I would expect more of the lights to be lit on the dash . Including the check engine light , battery light . This are not connected , Power or ground wise . Have the vehicle checked for codes , that should be the first place to start any diagnostic's always !

Elizabeth: It could be the power train module. This is a computer that tells the drive train everything (like what gear to be in and how much gas to add). Part of the power train module goes to your dash lights. It is usually located underneath the center console, or under the driver's seat or sometimes under another seat. You can go to the wrecking yard, get one that is for your trailblazer and try that.

change the ABS relay should be done the side of your pump.in the engine bay.

Get rid of it, Let somebody allse deal with it.

internal transmission problem, abs is brake issue.
is 4x4 auto shift or can you select range?

You could have some major electrical problems or it could be some thing simple. You need to have the codes read and repost. then we can help you. Getting the codes is the most important thing that you can do to let us know where to start.

How old is your car? When did you have it serviced last?

tyr it in netral

Check the main fuse box under the hood on the drivers side. You should do it with an ohmmeter. good luck. The cruise control is probably the door lock module. Are your interior lights stuck on?