I just bought a used 2006 Volvo S40 2.4i, but on the way out, it started acting up and the motor died (as if we had a dead battery and no alternator). The lights in the car were on, and we could turn the headlights on, but the dash went dark or gave various error messages. When we would try to start it, it would just click, like a dead battery. We would jump it off, and it would start and run for a few minutes. Then the gauges would start acting a bit odd (tach and speed would bounce up and down, from 0 to about 500 rpms on the tach, and eventually all go off). But, you could feel the engine was actually still running, but very low RPMs and rough, and 15 to 20 seconds later, it would die. We could then jump it off again, and the same would happen.

Spent yesterday trying to sort it out. Could not find any obvious problems (broken grounds, shorts, etc.). If you disconnect the alternator, she will start up and run just fine (I guess untill the battery dies). If you connect the alternator back up, she acts up again.

Has anyone ever seen this or have an suggestions? Thanks!!!

 

Certainly sounds like a bad alternator or bad battery or bad connection between the two. This car is super sensitive to proper voltage. When running did you check the voltage at the battery? It should be around 14.4 volts with the engine running.

 

Thanks for the reply. We pulled the alternator today, but had no luck finding one to put in. We had already tried a different battery with no difference. Now I just have to find a replacement.

 

Do you have an alternator rebuilder near? Many towns have a company that rebuilds alternators.

 

Yes, but they were already closed yesterday before we could get it to them. We'll probably take it to them on Monday to have it rebuilt. But, I'm a bit nervous since I've seen so many messages about how finicky Volvo's are. I'm afraid that a typical rebuild shop might not be the fix. Is there a computer in the alternator that could also be damaged, or will a regular rebuild fix the problem? Thanks!