2005 Chevy Colorado 4wd don’t work ! There’s no selector lights on 2wd,4hi,4lo lightening up.repaced motor on transfer case and transfer case control module ,all fuses and grounds good ..any ideas

Four wheel drive actuator may me at fault, try park the truck on a slick surface like wet grass, set it in neutral and activate 4hi and 4lo back to 2wd a few times, if doesn't help try tapping on motor actuator located on transfer case while someone activates selector, park surface must be as level as possible, a good tip is to activate your four wheel drive once every few months to avoid it freezing up.If nothing helps then it needs to be diagnos by a tech. good luck

Put truck in Neutral while key in run position engine off or on (doesn't matter which). If it's pushbutton 4wd then try hitting 4low again. if that doesn't work some of the chevy trucks required you to press 4hi to get into 4high and then press 4hi again to get back to 2hi, unless yours has a 2hi button. In that case press 4hi to get into 4high and then press 2hi to get back to 2wd. either way you need to be in neutral to get out of 4lo. I have shift on the fly (Mechanical Shifter on floorboard for transfer case) on my 1990 Suburban and still have to put it in neutral to get out of 4lo. Good Luck.

THE TRANSFER CASE MOTOR IS ONLY FOR 4WD LOW. That would have never been the problem as soon as you confirmed it shifted into 4wd Low. 2wd and 4 Hi work off of vacuum. You may have one or two issues. A vacuum leak up by the front axle that engages the 4wd HI or the sensors on the transfer case.

Have you tried putting it in neutral and then selecting 2 or 4 wheel drive?

You have to put the truck in neutral first then switch the 4hi and don't use the auto select. If it still won't switch you may have damaged the servo and need to replace it. Or worse damaged the transfer case. So try in neutral first and hope that works.

There may be vacuum lines running down to the hubs. If so check them for vacuum when engaging and dis-engaging 4 wheel. If you can't feel any vacuum, trace lines, and check for leaks.

Your brake an CV joint issue can't an won't cause your 4X4 problem . The 4x4 system has a control module which supply's B+ voltage to the switch . Checking for codes in the 4X4 control module should have been the first step . Your best bet , take it to a qualified repair shop . You don't have the knowledge or test equipment to fix this.
SERVICE indicator (4WD/AWD) Lamp
The SERVICE indicator (4WD/AWD) lamp is an integral part of the cluster and cannot be serviced separately. This lamp is used to inform the driver of the vehicle of malfunctions within the automatic transfer case (ATC) system. The SERVICE indicator (4WD/AWD) lamp is controlled by the transfer case shift control module via CKT 1567.

Transfer Case Shift Control Module
The transfer case shift control module uses the VIN information for calculations that are required for the different calibrations used based on axle ratio, transmission, tire size, and engine. The system does not know which calibration to use without this information.
The direct battery supply line (CKT 1640) provides the power to the module and motor circuitry.
Transfer Case Encoder Motor
The transfer case encoder motor consists of a permanent magnet (PM) DC motor and gear reduction assembly. It is located on the left hand side (drivers side) of the transfer case. When activated it turns the sector shaft of the transfer case (clockwise or counter clockwise) to shift the transfer case. The encoder motor is controlled with a pulse width modulated (PWM) circuit within the transfer case shift control module. This circuit consists of a driver on both the Motor A and Motor B circuits. The encoder motor is bi-directional to allow the motor to shift the transfer case from 2HI or 4HI to NEUTRAL and 4LO positions.
Do you know what DTC'S are ?
DTC B2725 ATC Mode Switch Circuit Malfunction
DTC C0300 Rear Speed Sensor Malfunction
DTC C0305 Front Speed Sensor Malfunction
DTC C0308 Motor A/B Circuit Low
DTC C0309 Motor A/B Circuit High
DTC C0310 Motor A/B Circuit Open
DTC C0315 Motor Ground Circuit Open
DTC C0323 T-Case Lock Circuit Low
DTC C0324 T-Case Lock Circuit High
DTC C0327 Encoder Circuit Malfunction
DTC C0367 Front Axle Control Circuit High
DTC C0374 General System Malfunction
DTC C0376 Front/Rear Shaft Speed Mismatch
DTC C0387 Unable to Perform Shift
DTC C0550 ECU Malfunction
DTC C0611 VIN Information Error

Check the fuse to the 4x4, if the fuse is good then check the 4x4 electric motor actuator on the transfer case. You should hear it work from 2wd, 4hi to 4low and back to 2wd with the push of the switch. if you don't hear it working then check the wire harness at the actuator motor, look for any damages like corrosion or cracked wire connector clips. If the 4x4 actuator is working on the transfer case, then the front hub 4x4 actuator may have gone bad and that's located on the front differential. It's common for the clip there to corrode and break and is an easy fix with a new collar pin, at worst it's the diaphragm on the vacuum actuator that is located under the battery tray. There is a vacuum switch on the top of the transfer case, driver side but when that fails, your front hub stay's locked in the on position. Good luck and keep me posted and hope it's a simple fuse that has gone bad. You can pick up all these parts at Auto Zone or Parts Source and they will have the step by step instructions for you to get the job done with common tools.

If they are blinking I believe it means that there are fault codes present in the pcm. You need to get the computer scaned to see if there are an codes present. If you live near an Autozone or Checker autoparts they can scan it for free.

what causes the 4wd to kick in when you have it in 2wd