C900 T (85) Alternator/Battery Light comes on after shutting car off

off as in you take the key out of the ignition or as in you turn off the engine but the key is still in the ignition?

Then also the oil pressure light should come on...

Did you replace it with a same type SAAB alternator? I noticed not all alternators have the same 3 pin connector on the back, that is, the connector is the same, but the pins are wired differently. Why did you replace the entire alternator? It is usually enough to replace the brushes/voltage regulator assembly only.

I solved that problem by making sure the black box sitting on the back was plugged in properly.

Now to figure out why the low voltage light stays on when the vehicle is turned on.

I bought a digital multi-meter to test the resistance between the Alternator and the block(I have placed one end of the cable on the Alternator, and one hooked to one of the allen bolts which attaches the alternator frame to the block. If there's a better place I should put it, lemme know!) The wire is a 4 gauge wire, and should be more than ample enough to power it.

Since I know exactly nothing about how to use a multimeter, I made the guess that I'd put one lead against the end attached to the alternator, and the other lead touching the bolt that attaches the alternator to the frame.

(if anyone can explain how to properly use a multimeter for this application, it would be appreciated.)

The resistance readout I get on the 200 setting is 0.04 (From what I understand, this is good.)

However, now I see the positive lead(coming from the starter) is starting to spark at the alternator. Maybe I don't have it tacked down hard enough.

If anyone has any ideas.. lemme know.

Thanks much to all!

-LC

Check your grounding strap at the engine and the frame. Make sure the starter is also properly grounded to the engine.

It is not as complicated as it looks - but - you really need to lay your hands on a manual with electrical values for the car to use it effectively.