In the fall I got a free 240 from the girlfriend's parents. It was my girlfriends brother's car and they started having the battery not stay charged. First thought was the alternator, so I searched around and found that the voltage regulators seem to go bad.

I ordered a new regulator and installed it. After that the alt seemed to work because the battery was reading 14ish volts when hooked up with the car running. This was in November 2013.

Due to the harsh winter and no garage the car sat in the street until last month. Now it won't charge again!

With a battery fresh off the charger the car runs great, but starts to lose charge right away with the car running. I know the battery is good because it is pretty new.

I am not much of a mechanic, so I am new to alot of this stuff. The belts look like crap, but seem to work. No squealing or anything. The alt appears to spin correctly when the car is running, and spins freely by hand when the belt is off the pulley.

Previous models seemed to have the alt in a nice easy location to work on, but since they added injection they moved it down under the block on the passenger side. Its a huge pain to access. Installing the voltage reg was tough and I started to try to remove the whole alt today so I could get it bench tested. This proved to be very difficult with really stubborn mount bolts without much room at all to turn wrenches.

Before I remove the whole alt should I just replace the belt first? Can improper belt tension make it spin, but not actually create a charge?

IDK how sitting for 3 months could make the alt not work with a brand new voltage reg installed before the winter.

 

How tight were the belts on the alternator?

 

Does the battery idiot light on the instrument cluster come on when the key is turned to the II position and the engine off? This light has to be functioning in order for the alternator to charge.

 

Yes..

 

Google basic alternator and battery testing.

The voltage regulator is the common failure to volvo's. I have also seen wiring insulation at the alt. crumble and fail. Also going further in the wiring loom done accross the front of the engine wiring issues. But all these would be pin pointed with basic alternator/ battery testing.

Plus a new battery means nothing, sitting discharged Kill batteries real fast. It needs to be tested properly.

 

if the alternator has badly worn commutator rings, it will eat the brushes on a new regulator rather quickly.

 

Ok, so I put in a brand new alt yesterday. Now the car runs alot nicer, but IT STILL WON'T CHARGE!!! Battery reads 11.5v on the posts when running. Should it be reading much higher if it was charging properly?

I assumed it would read like 13-14v when charging, but maybe I am mistaken?

 

whatever your battery voltage is at rest, it should be about 1.2-1.5V higher when its charging. 13.6-14.1V is nominal for a fully charged battery.

stop the car, turn the key on, volt meter black - lead on the alternator body, red + lead on the D+ wire from the idiot light, do you read +volts ? (should be close to the battery voltage). now put the - lead on the chassis ground, like the fuel injection rails where there's a couple ground screw, do you still see + volts on the D+ lead?

if either is no, time to investigate why.


start the car, black lead on the alternator body, red lead on the big B+ terminal, see anything?

 

Threw a part at a car and it didn't fix it, who would have thought that doesn't work.