The Dark time of year

 "Control thy passions lest they take vengeance on thee." - Epictetus

Solid advice there.   This is not a deep philosophical post about winter and heavy thoughts.  Nope, it's about getting the damn dash lights to work in the Subaru - my beloved POS commuter car.  I only notice this in the winter months, and it's been annoying me long enough that I've finally decided to correct it.  

...and once again the Subie has been kicking my butt!

A couple of tiny T3 light bulbs are out on the climate control module on the car, and it's difficult to find the slider and fan switch for the heater in the dark months of the year - when you really need to use the heat.  The backlighting bulb for the push-buttons still works, but that's the only one.

Below:  The actual view while driving in to work.
 

 Call me crazy, but I decided to get a complete new climate control module off eBay, and replace the lights in it, then just swap out modules.  I liked the idea of damaging a spare, rather than the one I need to use.  Also, I figured that at least there would be spare parts if things went sideways.  The plastic is getting pretty brittle, and getting things apart and back together without damage is not a sure thing.

The new module arrived, and took it apart.  At one point I was struggling to get the back off, and it finally popped loose.  Parts flew all over the table and onto the floor, and I had no idea where they belonged.  The husky found one washer that I missed, and I made her spit it out.  The husky and I may have missed some other flying parts - I have no idea.

I removed the incandescent bulbs without even bothering to test them.  I'm only going to tear this down once for bulb replacement.  Below:  Front side of the climate control module with the face-plate removed.  The bulbs were located at the top center, bottom left and just below and right of the fourth white switch - you can see the holes.

 LED bulbs are a pain in the butt in automotive applications though.  They are polarity-sensitive.  An incandescent bulb can be installed in either direction, but an LED can only go positive-positive and negative-negative, or it won't light up.  When the climate control module is on the bench, it has no power, so you can't tell if you got the LEDs installed correctly.  

I figured out the correct polarity of each LED using the bench-top power supply.

However, I had no wiring diagram for the climate control module, and I was too chicken to randomly apply 12 volts to connector pins and hope I could get the LEDs lit without first melting something in the unit.  Figuring out which pins were power supply to the circuit board by following the traces to the LED holes was impossible, and it still wouldn't guarantee I got the polarity correct.

Instead of trashing the new unit with my power supply, I went into the dash and unplugged the old unit and plugged in the new one, then installed the LEDs with the ignition and dash lights on, until all three bulbs lit up.  Below, it's on the bench, partially assembled, with the new LEDs installed in the sockets - with the correct polarity.

 Eventually, after a lot of trial and error, I got the climate control unit re-assembled - with no spare parts laying around afterward (shocker, I know).  All the push-buttons worked correctly, the slider moved the heater arm, and the fan switch rotated smoothly.  Time to install.  Or not.

The old module wold not come out of the car.  Unfreaking real after all that trouble.  I could not remove the clip that holds the heater door cable.  It's deeply embedded.  I put a lot of force on the clip and bent it quite a bit, but it would not come free and release the cable.  Rather than damage the thing and have no heat control, I re-installed the original module and called it quits for the time being.

I will have to try this again when I have some more time, but right now I don't want to damage the one module that I'm certain works, even if the lights do not.

Updates will be forthcoming on this latest saga of the Subaru.  I might, MIGHT, get into the instrument cluster next, even though it has no burned out bulbs, if I like the results of this project.  It will also almost certainly be a pain in the butt, from the standpoint of figuring out and testing polarity.

Another pain in the neck is I get comment spam every time I do a post about LED lights.  Look for it!

EDIT 25 December 2021 (yes, Christmas Day)

Got er done - and it's pretty bright!  I went to the hardware store and bought several sizes of "E-clips", in case I damaged or lost the one in the old unit.  Good thing I did, because the old one fell inside the dash and I couldn't locate it! 

View in the dark before driving to work.  It's now quite a bit brighter than the instrument cluster.

At least it's better than it started out (below)

I also changed out LEDs for the dead bulbs in the rocker switches for the heated seats, which was another project that should have had its own post.  They don't make anything very easy.