93 240 with ground wire in wrong place?

[240Dad]

I was changing out my alternator on my 93 240 (173K+ miles) today and found an extra wire under the alternator. It is attached to a nut that holds the alternator housing bracket on on one end and has a broken round eye terminal at the other end. It is the blue wire in the picture. Forgive the poor quality but I was in broad daylight in a grocery store parking lot changing out the alternator. At least I had Rush to listen to on my truck radio.
It is obvious where the red wires go but what about the blue wire? It is too short to reach much more than the frame or the alternator.
Thanks,
Bill

Groundwire.jpg (16.25 KiB) Viewed 2293 times

[billofdurham]

The wiring diagram doesn't show a blue wire on the alternator circuit. There is a red from the starter and a red, which splits, to the light on the dash, SRS control unit and ABS control unit.

Perhaps a previous owner has used the alternator bracket as an earth (ground) point for something else.

Bill.

[240Dad]

Thanks, Bill.
That is kind of what I thought but wanted to put it out there to see if one of you Volvo sages might know. I will remove it so the next guy won't waste time wondering.
Thanks again,
Bill

[drsugg]

Well, I would bet your old alternator was OK. If you look closely, you see the alt is mounted with rubber mounts. Leaving off the "ground" will not allow it to complete the circuit. I have fixed many alternators by repairing or replacing the broken ground connection.

[240Dad]

So, if the blue wire is a ground for the alternator, is there a ground lug that is obvious?
Maybe I can answer my own question but I would still like confirmation. There are two threaded holes in the back of the alternator. One is where what I think is the capacitor attaches. Next to it is a somewhat bigger threaded hole. Could that be where the blue wire attaches?
Thanks,
Bill