Steering wheel controls getting weird

ive recently noticed that when i turn my headlights on my steering wheel controls get weird.
heres my situation:

Headlights - on

Occasion 1
volume down - works
volume up - nothing
back track - nothing
forward track - does what the back track button is supposed to do

Occasion 2
volume down - nothing
volume up - works
back track - does what the volume up button is supposed to do
forward track - does what the back track is supposed to do

Headlights - off
everything works as it should

any help or insight as to where to start chasing this gremlin would be much appreciated

 

If you have the factory head unit, I would name that as the #1 suspect. The way the steering controls work is that each button has a separate resistor value, and when a button is pressed, the head unit detects the Ohm value coming over the wire and translates the input accordingly. The factory head units are prone to odd behavior over time (buttons on the head unit not working/doing the wrong thing) and it would not surprise me in the slightest if yours was having issues with the steering wheel inputs as well.

There's no fix for the head unit itself, short of tearing it apart and doing low level component checks/repairs - the fix is to replace it with a used factory unit ($$$$/likely to die again) or an aftermarket unit.

 

i have an aftermaket headunit, all of the controls have worked with no issue for about 2 years, started acting up a few months ago

 

Then you may want to pop it out and check the steering wheel controls. It would be a matter of using a meter to verify the resistance of each button over the two wires on the vehicle side harness - I don't have a pinout or expected ohm values handy but I bet @caribe makaira does.

If the values are not as expected, your problem is either resistors gone bad (unlikely), a faulty/sticking button/contact, or an issue with the clockspring causing intermittent failure.

 

cool thanks, later today ill pull it apart and see if i get different readings for each button press

 

Well, you'll also want to make sure they're the correct different readings. If one button is sticking, it will cause them all to be off by that amount, e.g. if an 80ohm resistor is sticking, one that is supposed to read 50 to read 130, etcetera.

 

sounds like i need to test it with the headlights off and then see if they are different with the headlights on