Hello long story. My Volvo C70 has some kind of voltage issues when turning the steering wheel that are getting worse over time.

here are some videos that sort of demonstrate but its hard to see.

https://drive.google.com/file/d/1hZrkQ_kjK3XZP-Vq4rK6uDHfQBgMarQZ/view?usp=drivesdk

https://drive.google.com/file/d/1heCNbSc9TbAg4ZMlPdQ1S6_hHRd960F0/view?usp=drivesdk

All i am doing in the videos is turning the steering wheel while idling.

This issue has been going on for a few months now and is a long story. I'll try to explain as much of what has happened as i can think.

Basically, what has been happening is intermittently the dash, radio and park lights flicker (but not the main xenon headlights). The video doesnt really capture the flickering too well for some reason, it much worse in person.

While its flickering, if i turn the steering wheel the flickering gets worse and everything dims. Also, while turning the steering wheel, the radio occasionally cuts out and sometimes i see an alert that the anti skid has temporarily stopped working. The engine rpm will also drop, sometimes it nearly stalls but always manages to recover. Very rarely, while turning I've seen the xenon headlights go out for a couple seconds then come back on.

After being a minor inconvenience for a few months, i recently went to start my car and it wouldn't start. I could hear the starter ticking like as if the battery was flat (at this point the battery still had charge). And the dash came up with multiple errors. 1st was that brakes had failed, and secondly that the immobilizer was activated. The doors then started locking and unlocking repeatedly. If i pumped the brakes, its error message went away but came back if i turned the key again.

After turning the key several times and nothing improving, I tried to take the key out but it got stuck at acc and wouldnt come out. The dash went black except for a flashing yellow message light. If i turned the key back the other way, the car would not start. Nothing happened.

I was forced to leave it like that with the key in the ignition. Eventually i checked later and the flashing had stopped becausr by this point the battery was completely dead.

Since the battery was 3.5 years old, i decided it was time to buy a new one anyway. So got a brand new battery and put it in. The car powered up and it let me take the key out. All the errors were gone.

But the flickering and dimming while turning remained, although not as bad as before. But after leaving the car sitting overnight it went back to flickering bad.

I thought it might be the alternator, so i got it tested by an auto electrician and it passed their tests. They said it was charging the battery like its supposed to. It seems to be fine. But when i demonstrated the dimming lights while turning the wheel to them, they still wanted to go ahead and replace the alternator before looking at anything else. Might be the right thing to do, but since it passed voltage tests im no longer sure? On the day they had it the car was behaving somewhat better than normal. Only slightly dimming but no other issues but after i picked up my car and left it got really bad.

One other thing i noticed was that if i revved the car while turning the wheel, the radio will cut out, but then when it comes back on, the flickering is gone. But if i let the car idle for a few mins, the flickering comes back. This is only while parked up.

Which suggests to me that maybe it is the alternator, except that if i rev the engine but dont turn the wheel, nothing changes. And while driving the flickering will not go away.

Lastly, I didnt catch it on video, but afterwards i went to turn the car off. I turned the key to acc and the engine shut down roughly like it had stalled, the dash went out, no time, milage, or anything else, completely black. The doors locked, and the windows wound down a little bit, and the key got stuck in acc position in the ignition. Just like last time, it wouldn't move to off. There was also a ticking sound coming from the fuse box in the passenger footwell that went for a few seconds.

I turned the key to the right to try start the car again and nothing happened for a few seconds but then all the power came back and everything went back to normal. It then let me take the key out.

Milage is 91,000km, automatic transmission. As far as im aware, it is the original alternator. I do not know if any of the belts have been done either. Probably not. Im the second owner with no service history from the previous owner.

So yeah, kinda crazy...

Should I go ahead and replace the alternator like the shop wants or do i need to go somewhere else that is willing to investigate other possibilities?