73-87 electric wiring gurus?

[chevybuilder18]

Ok so i just installed my serpentine belt drive to my 350 sbc and its all in good shape all aluminum brackets and i need some one to tell me how to hook up the alternator connector which i have for the CS130. I know the S and L wires hook up some how, alternator is on passenger side, ready to be wired up. everythings lined up no problems except i had to make a bracket that ran from intakes bolt hole in the middle that held the old alternator bracket in place to the back of my new CS130. needless to say im pretty happy with it, and i have yet to test this. the tensioner works and everything. Now thats out of the way, can a eletronic guru tell me what these S and L wires do and what way i should hook them up to my already existing SI alternator with internal voltage regulator connector?

[chevybuilder18]

Ok im just gonna post my question a lil easier cause i tend to confuse people. But the question is what does S and the L wires do for the electrical system? sorry if i confused anybody by original post

[hatzie]

http://www.nastyz28.com/forum/showthread.php?t=144477

[chevybuilder18]

http://bob_skelly.home.comcast.net/~...ternator1.html hey i was curious if the wires that ran to the SI style 3 wire were how i was supposed to hook up my CS130 in my truck

[chevybuilder18]

"Wire 1: Field Excite/Warning Light Indicator Input

This terminal is fed by the switched 12V source (from the ignition switch and through the ignition warning light indicator or "idiot light"). It is used to energize or excite the field windings inside the alternator. The alternator cannot start charging until there is voltage on the field windings and a magnetic force is created. In addition, this terminal will cause the ignition warning light to illuminate if the ignition is turned on and the alternator is not supplying enough voltage.


Wire 2: Remote Voltage Sense Input

The sense line is used by the internal regulator to determine how much voltage is present in your charging system.

This sense wire can be connected (theoretically) to any point in your system, but it is should be connected to a main distribution point such as the power terminal post near the battery for best performance.

The photo at right shows an example where the sense wire is looped directly over to the BATT terminal. This is a common configuration used when retrofitting the Delco SI alternator and does not require any in-depth understanding of the car’s wiring system.

While this is the simplest connection location for the sense line, it is also the least desirable: the alternator will sample the output voltage at the alternator itself instead of at the load connections further downstream. A voltage drop downstream of the alternator due to the internal resistance of the wires and components is not accounted for in this scenario, and the voltage at the battery may be lower than it should be.

This approach will work, but it's not the best solution.

It is better to run the sense wire away from the alternator and over to the power terminal post near the battery. This will ensure that the system voltage is properly maintained.



For illustration, let’s say the regulator is set to maintain 14.4 Volts. The alternator will do it's best to maintain 14.4V at the point where the sense line is connected. Let's also say that we have a battery feed cable that exhibits a 1V voltage drop across its length (see illustrations below).

If the sense line was connected directly to the rear of the alternator to the BATT terminal, then, with the 1V drop in the cable, the far end of the cable would measure 13.4V. At this voltage, the battery would not be receiving a full charge and the car's accessories wouldn't be getting optimum voltage:



On the other hand, if the sense line is connected at the far end of the battery feed cable like in the figure below, then the voltage at the terminal post will be held at 14.4 volts. And, the voltage at the BATT terminal at the alternator would read 15.4V. Why? Because the alternator must boost its output voltage by 1V to overcome the voltage drop in the main output feed on its way to the power terminal post. This is better!



NOTE: When using the remote voltage sensor, you should not make additional electrical connections at the BATT terminal of the alternator since the voltage there will always be somewhat higher than the regulated value. Instead, make all additional connections at the point where the sense line is attached.



Wire 3: BATT Output

This terminal is for the alternator output and is usually a threaded stud located on the rear of the alternator. A heavy-gauge cable is connected to this stud and usually connects to the positive terminal of the battery, or to the power terminal post near the battery on the E-Type.

Note: the gauge of the cable connected to this post must be large enough to handle the alternator’s maximum current rating. If replacing the OEM alternator with one of a higher amp rating, it is imperative that this output cable be replaced with a fatter one."

I see the photos have given me a sence, so thats all i have to do is Hook L up to the field wire in my truck and my S wire to the Sensor wire that is right beside it?

[gchemist]

The alternator only needs power to the L terminal. Power from an ignition source is enough. It only needs 12 volts to kick on. I have mine running with a light. When the light is on, the alternator is not charging. When the lights goes off, the alternator is charging. Great way to know if I throw a belt or there is a charging problem. I run the power wire directly to the battery. I use a heavy duty wire.