While in the shower this morning, pondering the blinking light, I think I figured out why my battery warning light may be blinking.

S70 Serpentine belt path is Crankshaft, tensioner, P/S, A/C, Alternator, Crankshaft.

The S70 uses a 2 sided ribbed belt. This is because the alternator path is above and to the left of the A/C and this path maximizes the contact surface without adding an additional idler. This path causes the the alternator to spin counter clockwise.

The belt I put on has 1 ribbed side. It contacts the alternator on the right side causing the alternator to spin clockwise. While this makes no difference to the alternator itself, it may make a difference to voltage regulation or the warning system. The diodes should clip the voltage in either direction. I suspect this is what the batgtery warning light is trying to tell me when it blinks.

I'm going to see if I can get a 2 sided ribbed 495 belt and see if there is enough contact surface, if any surface at all if the belt is moved to the left side of the pulley. It didn't look like it, but it might be enough contact to turn off the warning light (assuming the alternator is still good) and may even offer enough charge to keep the battery charged up.

 

Make sure you take a look at a belt diagram to insure that you route it correctly.

 

I wish I had taken a picture of it but I didn't think to do it. I did find an online picture of the routing; here is the link to it.

I need a diagram for a S70 serpentine belt routing - JustAnswer

This is exactly what it looks like on my vehicle. Note that the generator has to run on the "backside" of the belt which is why it has ribbing on both sides of the belt

Can't find a 2 sided 490 or 495 belt and I still don't think it would work right since the contact surface would be very small. A friend said that sometimes you can run the alternator from the backside of the belt. Maybe termporarily, not sure.

 

My last contrabutoin on the subject..... hopefully.

I moved the belt to the left side of the alternator pulley. This spins the alternator counterclockwise. It definitely does not have good contact and I don't know how it would go if the load from the alternator was high.

The 6K495 belt was too long. I had a 6K490 belt and that fit. I think a 6K485 (if it exists) would be tighter.

The battery light is still blinking but when I started the car I had 14 volts on the battery, after 5 or so minutes I had 18 volts. Yes, I know those numbers are not good, but I checked may meter on my wifes car and she was 17.7 volts (not running) and 20.2 volts (running). I know - time for a new meter. But the net result is I think its working. I'm going to start a separate thread on the bagttery light