Did the hacksaw repair to the intake manifold after the nipple on the intake that coolant reservoir return line connects to snapped off, got the metal replacement back on but made a mess with the coolant under the hood. After air hosing everything off as best I could the car still wouldn't fire. I pulled plugs to check for spark and when putting the plugs back in the car there was a loud pop from somewhere under the brake booster area. I got the plugs in and everything reconnected and after some cranking she fired and ran. I don't know what the pop was but I took it to work to make sure everything else was ok as it has sat for a few months and as I got to work the Service light came on for a few seconds and then went out, but when it went out the whole instrument cluster went dead. Needles and everything froze where they were and I had no turn signals. I got in the parking lot and shut off the car for a moment, then turned the kay to on and the cluster lit up as normal but the battery was too dead to roll the motor over. It seems that the pop may have been a fusible link? Is there a wire from the Alt to the battery? I saw when replacing the starter a few weeks ago there was a wire from the Alt to the starter but I didn't see one from Alt to battery... Rock Auto doesn't have a fusible link listed, so any details are most welcome.

 

The fusible link is between the starter and alternator.

See attached pic

From

2000 SL2 Fusible Link Location

Did you do the rinse down w the battery connected?

 

Oh excellent! THANK YOU! Anyone got specs on it in case that is the culprit? Need to get it back home and check for continuity between starter and alt.

 

The fusible link in the wire between the starter and the alternator is to protect the alternator from jumps starting with the cables reversed. Your car has a 90 amp alternator so you need that much protection. I suspect that you will find a 10 gauge power lead and a 16 gauge fusible link section.

 

So I removed the fusible link that goes the short distance from the alternator to one of the thick posts on the starter and tested it (having finally found where I hid my multimeter on myself), and found that it has continuity. It is my understanding that the two heavy posts on the starter are for the battery + and the alternator respectively, and the smaller post is triggered by the ignition switch via the purple wire? I didn't test that the two heavy posts were connected when I was under the car. I ended up using the same post for the alternator and battery, and everything seems ok. The car shows around 12 volts at battery when off and jumps to around 14 volts when running.

 

You have connected it correctly this time. The alternator wire connects to the same post as the battery cable. The other large post on the starter only has power when starting the engine. The small wire comes from the ignition switch and signals the starter to start. Simplified instructions.

 

Ah ok. Then what was connected to that other post? Nothing?

 

The other large post is power from the solenoid to the starter motor. No extra wires attach to that post.

 

The post that is not connected to the battery and fusible link has a thick piece of braided copper that should be covered with some type of insulator like heat shrink. This is a short wire that carries current from the starter relay contacts to the rotor winds.

When you turn the key, current flows to the small purple wire into the starter relay which energizes a coil wound on a steel core. The magnetism created by the current flow pulls in a switch contact which allows a big current to flow from the positive battery cable into the contactor and then into the braided copper wire on post 2 and finally into brushes and rotor which creates a mag field which is opposite in direction to the permanent magnets that sit against the starter casing. The force created by the opposing mag fields is what spins the starter.

The starter relay is a sore point in a lot of Saturn's. The turns count of the relay coil is a bit low. So any resistance crested by deterioration in any of the connections involved in the starter circuit, be it the ignition switch, the fuse box, the ring terminal at the end if the purple wire, the grounding of the starter, the condition of the battery or alternator, the engine grounds or the battery cables can cause intermittent starter operation.

I popped the relay apart and rewound the relay coil with smaller wire so I could get more turns on there. Magnetomotive Force ,MMF, or just plain F is equal to NI, where N is the number of turns of wire on the coil former and I is the current. So if you increase the turns count, you increase the MMF. You have to be careful here as when you decrease your wire size to get more turns on, the resistance goes up, so it is a balancing act between turns count and wire size in order to increase the force that pulls in the contact. I had to JB weld the relay back onto the starter as their are no bolts holding the relay on, it us a pressed fit. I. Never had any problems after that, going on 20 years now.