Stock Radio (Hu850?) - Display Dims, Control Lights Off And Steering Wheel Controls Don'T Work

[jellyfishhal]

2003 V70 - this began about a year ago. Used to be more or less readily "fixed" by pulling fuse and putting it back in. Like some kind of re-boot or something. Has gotten worse - maybe after I've driven the car for a long while, if I pull and then replace the fuse, the displays light and the steering wheel controls work. But after shutting off car, returns to dim/no display and no steering wheel controls. Mechanic says forums all stumped but I can't even find a similar topic. Anyone else?

[MyCarIsRed]

2003 V70 - this began about a year ago. Used to be more or less readily "fixed" by pulling fuse and putting it back in. Like some kind of re-boot or something. Has gotten worse - maybe after I've driven the car for a long while, if I pull and then replace the fuse, the displays light and the steering wheel controls work. But after shutting off car, returns to dim/no display and no steering wheel controls. Mechanic says forums all stumped but I can't even find a similar topic. Anyone else?

So once it works correctly, it will work for a bit, then switch back into dim/off/not working after a period of time? Do the controls on the HU itself always work or do they go out too?

Well step one is always check the wires and fuse. Are you using the right fuse? Don't EVER put in anything over the stated fuse rating, and while lower won't fry anything but the fuse, it can cause freaky behavior. Check the ground as well, and voltage at radio vs voltage at battery.

I think you either have a bad connection inside the radio,

a bad cap or other component inside the HU,

low (or high, but high would likely screw up lots of stuff) voltage at the HU/bag HU ground,

bad connection to steering wheel controls.

Those are your likely culprits. My guess is that you have something loose or a bad cap inside the HU, maybe a bad solder joint.

Have you ever replaced the steering wheel or column components?

Swap in another known good HU (after testing voltages and ground!), or if you're up to it, remove the radio from the car and take a look inside. It's out of waranty? pull the cover and look even deeper. Bad caps you can't see, but broken solder joints you can.

There is one more thing... Liquid/goo/nastiness inside the HU causing shorts and issues. Is there a cupholder nearby? Do you drink coffee? Coffee in a car dash environment tends to pool and turn into sticky goo, I've "fixed" more coffee-filled HUs than i care to remember.

Good luck! and post back your findings.

[pv70]

Have checked to see if the car or AUM (radio) is throwing any error codes? Unfortunately, they can only be read with vadis or vida.

Have you checked to see if the car or AUM (radio) is throwing any error codes? Unfortunately, they can only be read with vadis or vida.