Radio Volume knob overshoots !

i don't recall hearing this one before.

 

The buttons on my stock stereo only work half the time...I'll be upgrading to an aftermarket stereo in the near future.

 

there is a fellow here, selling knob extensions. i wonder if they would help.

 

Sounds like something is defective. The radio volume knob is not a regular potentiometer with a resistive strip and a limited range of motion. As it turns it provides a digital step to a controller which is supposed to increment/decrement the volume. Yours certainly isn't doing that. Something to check whenever you experience electrical funny business is the state of charge and age of your little 12V aux battery. Probably 4-5 years old now if it is the original. Maybe pull it out and have it load tested. And maybe the electrical reset might do something also.

 

Did you ever figure out a fix? My JBL system on my 2011 does the same thing

If I i press the knob up or down while turning it, it seems to work much better.

If I can find a system that works with the steering wheel buttons, including bluetooth calling, I'll probably upgrade to a new headunit. Just weird it does this!

 

The carbon strips inside the potentiometer residue scraps off over time from constant knob adjustment. In the audio world, knobs and faders go through the same thing, audio engineers have to spray the carbon strips to blow the residue and a protective layer coat is to preserve the carbon from excess stripping. When excess carbon residue builds up in clumps and the contacts touches it, this cause non linear volume/signal changes. Use caiglube deoxit and blast into the pot with knob removed.

 

Aren't there volume control buttons on the steering wheel?

 

The volume pot isn't a potentiometer , but rather a rotary shaft encoder! As with all things digital these days it generates an on/off square wave to adjust the volume. Either the encoder is becoming defective, it can be replaced, if you can find the right replacement. Or, the IC chip which receives the pulses is going bad. Since the steering wheel thumb switch seems to work seems to function properly, my first step would be to pull the radio out of the car, pop the covers and see if the rotary encoder has a mfg number on it, and search the interweb for a proper replacement. This fix is not for the feint of hart, nor the electronically/mechanically challenged! With that being said, the alternative is a trip to the dealer and replace the radio a they do not do component level repairs!

 

AzWxGuy- How do I do an electrical reset? My horn was only working if turned to the left. After visiting the dealership and told the part was $800 I left and decided to find my own fix. Now the horn doesn't work at all and the radio stopped working. Then this morning the radio turned on if I pressed one of the preset buttons. All the preset station buttons now act as an on/off switch to the same station. It seems to be there is a loose wire or electrical glitch. How can I 'reset' the electrical?
Thanks!

 

You might need a replacement 12 volt battery if yours is original. I just replaced mine not long ago. A weak 12 volt auxiliary battery can cause all sorts of electrical issues. That could explain why your radio isn't working properly. The intermittent horn issue is probably something else like a busted clock spring. This is a set of conductors wrapped in a spiral and placed inside the steering wheel column so all the buttons on your steering wheel operate things. You didn't say what service the dealer was going to charge you $800 for. Maybe it was this clock spring. There are other threads about clock spring problems. Quickest way to do an electrical reset is to find that little 12 volt battery in the right rear corner of your car and remove the negative post clamp for a minute or two. Good time to check the voltage on it if you can. This will also erase your trip odometers, your power window auto functions, your radio presets, and reset various volatile data stores in various ECU's throughout the car. Good luck.