99 2dr 4x4 Blazer LS, AT, no interior/electronics mods. Stock 1.5 DIN CD HU(non-Bose).

Here is what is not working ( as far as illumination): all radio preset buttons, hvac, and both door window/lock switch illumination are dead. hvac will not switch between defrost-panel-floor.

Here is what is working: Radio digital clock/display does work as does normal radio functions and dims with dimmer switch, instrument cluster and dome light also dim with dimmer switch. Dome delay also works when turning off ignition key or pulling exterior door handle. HVAC fan speeds and rear defrost work. 4x4 switch and indicators also work. Rear electric window release also works.

Checked interior and under hood fuse panels, no blown fuses. Recently changed master window/lock switch for a broken bezel (illumination issue was there before the replacement.)

Really not sure what the previous owner left me with, but do know there was a CB installed/removed. (i removed the leftover brackets)

Could this possibly be an issue with the BCM? I have searched the forum and others this week, and am looking over some of the BCM schematics found on here now.

I am finishing up the rear brake lines and rear caliper rebuilds in the morning, and i will tear into the dash to check wiring. Just thought someone might think of something other than the BCM.
Have checked the bulbs in the door switches and hvac, none blown.

Thanks in advance!!!
-Sean

 

I believe that the BCM controls the dimming of the clock on the radio while the ILLUM circuit controls the main back-lighting of all of the rest of the components including the buttons on the radio.

 

Thanks a bunch, swartlkk!!! I will post what I find.
I didn't get a chance to chase the electrical today. O'reilly shorted me one rear caliper kit, and was on a scavenger hunt most of the day. Luckily I found the only one left in a 100mile radius of me.

 

Here is an update on what I found... the hvac control panel had the big bottom center connector (the huge-*** white one with only 2 wires...lol) was pulled out (both clips broken). Got it to stay in temporarily. Ordering a new one.
The factory cd player was just crap altogether. I pulled the new Sony HU out of the bmw and installed it in the blazer.
Thank goodness it wasn't the BCM.
I have all illumination now.


Still haven't fixed the defroster/floor/vent selector, but that is a different issue. My under hood vaccum lines are a mess, dry rot and misrouted.