Just replaced dead alternator.. return of the dash message. Help!
 

Hi all,

Had my Volvo for a about 4 months now.. it's a 2006 v50 (auto). Last week I had the alternator replaced after the car broke down on me, which resulted in getting it towed. I'm not a full bottle on car mechanics, so excuse the dodgy or vague explanations here.. Just prior to the car breaking down I had the red exclamation mark come up on the dash and the battery icon light (alternator not charging- according to the manual) come on with a dash message saying "power supply service urgent". Within moments I felt the accelerator not responding and the lights flickered before I managed to pull over in time and everything went dead.

After getting it towed I had a mobile mechanic come check it out.. seems the alternator was completely fried, so we replaced that.. ($$). The mechanic was great, and helped me get it sorted really quickly. He also took the battery and put on drip (?) charge for the day before he came back with the new alternator and installed it. Here's the problem though...

After using the car for the last 4 days I just got the SAME warning lights and message on my dash. Not wanting to risk another tow I pulled over quickly, turned the car off. I then drove the car home.. bout 20mins in heavy traffic not getting above 40km/h. Fortunately no more warning lights. Called the mechanic to get his thoughts.. he said potentially an earthing problem, and also I few other ideas which I couldn't get over the background noise.. he'll be coming soon to check it out.

The other issue Ive had with the car, which has been great otherwise is a warning message and exclamation light coming up telling me to come to a stop or gear up or down. This is almost always happens when I put my foot down (though not always) / hard acceleration.

Having read about how complex the electrics are on these cars (17 computers??) I'm concerned the issues are related, perhaps to a regulator issue, especially since the alternator has now been replaced (with a factory part too).

Obviously I should have had the warning lights related to the transmission checked out already, but because it was intermittent and money has been tight I'd been putting it off.

Hopefully some folk here can shed some light on the above I've described, and also whether the issues could be related. Much appreciated!

agree with the tech that your alternator may have a wiring issue causing a floating ground. Newer cars sense voltage to know when to kick up the altnerator output and a bad cable, terminator etc can throw errors.

As to the warning light, you should have your mechanic scan the car for OBD2 fault codes. Usually the "slow down" messages pop up when there's some risk to the car (ie high number of misfires, a major sensor is out of range, oil pressure is dangerously low etc). There should be a fault code set indicating what is going on to trigger that warning.