Failing alternators

Post by **tiger240** » 02 Nov 2011, 14:42

Hello! I am the owner of a 1986 240 GL wagon. Recently, the alternator in it died and was replaced by me with one from an autozone. It, too, ended up not working and draining the battery. Since it was under warrently, I traded it for a newer alternator and also bought a brand new battery. The second alternator ended up failing soon after. Every connection was tight on both ends, but the battery would not charge and the dash light would not even light up when the key was turned.

I'm on my third alternator. Before I plugged it up, I tugged on the ground wire to make sure it was tight and I hooked it up. When I started the car, everything seemed fine for about 8 seconds. My oem volts gauge gave a great reading; but then the parking brake light (which was on in the first place because the brake was on) began to flicker and my oem volts gauge began to become erratic. The needle would shoot down to the 12 volts low range then shoot back up to the normal range, then shake a bit. I've come to the conclusion that this is the reason my alternators keep failing. Any ideas? I've attatched the ground wire to one of the posts holding the alternator together, should I have connected it to one of the positive terminals?

I'm at the end of my rope, any advice would be great. Thank you!

Post by **billofdurham** » 02 Nov 2011, 14:48

Welcome to Matthew's Volvo Site.

the dash light would not even light up when the key was turned.

Is the dash light still not coming on when you switch the ignition on? If the dash light doesn't work, possibly blown bulb or bad connection, the alternator will not charge. The alternator, or charging, warning light in the instrument cluster feeds a small amount of electrical current to the field coils in the alternator when you turn the key on and the engine isn't turning. This excites the coils (electromagnet) and the alternator gets the magnetic field it needs to start charging as soon as the engine runs.

Bill.

Post by **tiger240** » 03 Nov 2011, 09:45

With this newest alternator, the dash light is coming on when the key is turned. I had heard about the bulb and tried changing it back on alternator number two. With my newest changeout it now comes on normally and turns off when the car starts. I did forget to mention that when the charge begins to become erratic, the light does not turn on or flicker. Also, the car seems to be running normally when the charge becomes erratic.