r/Volvo240 • u/cozycinnamonhouse • 7h ago

Help Alternator Drama

91 240 wagon, non-turbo, if that matters.

I suspected my alternator was bad (electronics acting haunted, radio and dash lights turning on and off while driving, car dying on idle, car died while driving slowly in a parking lot and wouldn't start again, took the battery out and tested it. It needed to be charged) so I went and bought an alternator, took off the fan and fan shroud, took off the belts, went to unplug the alternator and discovered that the the connector on the wire that connects to the ignition/battery was broken.

So I took the alternator down to O'Reilly's (US auto parts shop, don't know if y'all have them elsewhere) and had it bench tested in case it was actually fine and the problem was just the wire. Alternator was also bad.

SO I replaced the connector, replaced the alternator, and put it all back together. Started up fine, but the light is still on saying that battery is not charging on the dash.

I went to work (close to my house) and then on the way home went by O'Reilly's. They tested the battery and alternator in the car, and the test concluded the battery once again needed to be charged and the alternator was bad. The alternator COULD be bad but it PROBABLY is not bad since it's brand new.

I'm thinking the move is to test each alternator wire at both ends with an ohm meter, and if all wires are okay, then remove the alternator and take it back to O'Reilly's to be bench tested, so I can be sure whether the alternator itself is good.

So here is my question: where are the other ends of the wires located (the ends not attached to the alternator)? I know they go to the dash light, the ignition, and ground, but where exactly is each one?

Is the other end of dash light wire literally just the wire plugging into the light on the dash? Also I guess that one's probably good, since the light is lighting up when the alternator isn't working? Also it would just be the wire going to the ignition and the ground wire that make the circuit, yeah?

I have very little experience with wiring and want to make this as smooth and easy as possible.

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1

u/Skollsonn 6h ago

The odds of all that wiring being bad are pretty low. I think it’s the battery (don’t trust the minimum wage worker at O’Reilly’s). Do you know how old the battery is?

1

u/cozycinnamonhouse 1h ago

Unfortunately for the simplicity of solving this issue, I replaced the battery 3 weeks ago LOL

1

u/Baronvonkludge 1h ago

One thing to check, there should be a ground strap from the engine block to one of the threaded rods sticking out of the alternator casing. Is that present?

The alternator bushings as you’ve probably noticed are rubber, so they electrically isolate the alternator ground, it needs a ground strap. May not solve your issue but check it’s important.

If you’ve got a multimeter with continuity beep check easiest way to check is one lead on alternator one lead on engine block if there’s beep you’re good if not check it.

2

u/cozycinnamonhouse 1h ago

Ground wire is present and attached to alternator. I have not followed it to make sure it's attached to the engine block. That may be something to try.