On a 2001 Tracker the clock is built into the radio. In "day mode" the clock display is bright and the radio buttons are not backlit.
In "night mode" the clock display is dim and the radio buttons are illuminated. Here's why that happens:

In "day mode" the radio's internal relay's normally-closed contact connects the display directly to ground at pin A12. There is no reduction in current so the display is full bright. Additionally there is no voltage to the backlighting so the radio buttons are not illuminated.


The clock enters "night mode" when 12 volts are applied to the B4/B12 inputs. The relay energizes bringing the contact to the normally-open position. Now the display current is forced
through the dimmer resistor before it finds a ground at pin B5. This reduces the intensity of the clock display. The same 12 volts is also applied to the backlighting circuit so the radio buttons illuminate.


The radio receives the 12 volt input from the tail light relay.



The tail light relay is controlled by the headlight switch or the Ambient Light Sensor (ALS).


The headlight switch is a 2-pole 3-position switch. One pole operates the headlight relay, the other operates the tail light relay. In the OFF position neither relay is commanded ON.
In PARK only the tail light relay is energized. In HEAD both relays are energized. The ALS is a 2-pole 2-position switch in parallel with the headlight switch. In daylight neither
relay is commanded ON. In darkness, both relays (head & tail) are energized (no matter if the headlight switch is in the OFF, PARK or HEAD position).


Once the radio is in "night mode" the IP dimmer control comes into play. The dimmer control is essentially a transistorized motor speed controller.
Effectively it's a rheostat controlled by the thumb wheel on the dash.


This is a composite of the previous circuits (in "day mode"). In "night mode" the dimmer circuit will further reduce the intensity of the clock display and the backlighting. In "day mode" the
dimmer control has no effect on the clock display intensity.


The tail light relay supplies power to almost all of the Tracker lighting except the headlights.


All that additional backlighting is in parallel with the clock display and all of them are under the simultaneous influence of the IP dimmer control.
The full-size drawing can be downloaded at https://www.dropbox.com/s/o4s7t7ikdj...osite.jpg?dl=0

 

My tracker does not turn on the lights of the AC controls, nor of the buttons of the inermitent lights, rear defroster, cruise control, gear lever. What do I have to check?

 

The cockpit illumination is controlled by the TAIL relay. Check to see if your tail lights are illuminating when the headlights are on.
If the tail lights work the dimmer control is most likely bad.
https://chevroletforum.com/forum/tra...ts-out-106002/

 

It turns out that I disarmed and there was already a jumper between those two pins, if I remove the jumper the cabin lights turn on but the cluster lights turn off Haha

 

Can you post pictures? I'm not sure what you mean by "cabin" and "cluster" lights.

 

im sorry, “Cluster” is Instrument Panel and “Cabin lights“ is Cockpit Lights

 

This is my instrument cluster backlighting OFF and ON.

This is an example of my "cockpit" lighing OFF and ON. Both are controlled by the dimmer module.

 

When I turn on the headlights

Instrument panel backlight does not turn on

These do turn on

 

Is the backlighting for your HVAC control panel illuminated?

 

yes, it's on