CS 130 Alt Help?

[elks]

I have a 1972 C20. It is pretty clean however in recent time I have installed a new engine. Did a fuel injection from affordable fuel injection, HEI, etc. Last thing was a CS 130 alternator.

So I used this link to convert over to a CS130.

http://www.chevelles.com/techref/ftecref14.html

Hooked everything up and it worked great 14.6 volts running. Good power for everything including electric fans etc.

Next day went to start it up and battery was dead. Charged the battery and with the key did checked for amp draw. got 3.3 to 3.5 amps with everything off. So I started through the fuse pannel, no difference, disconnect ECU no difference, checked the HEI wire, no luck, pulled fan relay etc. Nothing was causing a draw.

When I pulled the 2 wire pigtail on the alternator the draw was gone. Did some more work. Disconnected (cut) the blue voltage signal wire and still a draw. The only time I get the actual draw is when the larger red battery wire is connected and the wire that is supposed to run from the battery terminal on the alternator and the black wire to the 2 wire plug are hooked up. this means that the only time I get the draw is when the larger red wire is making contact with the #2 terminal on the alternator. This is the little wire that jumps from the back of the alt to the plug on the alt.

Does this mean something is wrong with my alternator? Is that little wire supposed to complete a circuit in the alternator?

Thanks for any help I have tried to figure it out but have had no real luck.

[saxart]

I had an alternator that once did the same thing. (current draw) After having it rebuilt, it didn't have a current draw anymore, so "something" was wrong inside.

Is this a new alternator that you can return to the seller? If so, I'd contact them. If not, you may have to look at replacing/rebuilding the alternator you have.

Hope this helps...

[VetteVet]

What you are describing is not a CS alternator it sounds like an SI, the CS alternator has a four pin plug on the earlier models, and the SI alternator has the no. 1 and 2 terminals. Here is the correct wiring for both.


SI alternator.






CS alternator.




CS alternator wiring






How I do it for each.

SI wiring. Brown wire from the old external voltage regulator, or better yet from the firewall to the no. 1 on the alternator, and the red wire from the old EVR to the no.2 terminal on the SI alternator. You have it looped from the large terminal on the back of the alternator, which will work, but it is better to use the red wire from the regulator plug, which should be connected to the main junction, along with the large feed wire from the back of the alternator. This helps to compensate for the voltage drop loss down stream from the alternator as the various loads are drawing power.




If you have the 1 and 2 wires switched the battery will drain and if an internal diode is shorted the large red wire on the back of the alternator will short through the diode to the alternator ground and drain the battery.

With every thing disconnected, take a multimeter and check continuity on the large terminal on the back of the alternator, and then reverse the meter leads .You should get continuity to ground with the black lead on the alternator body, and the red lead on the large terminal, and when you switch them you should get infinity (no reading).

The CS alternator:



The brown wire from the EVR (firewall) goes to the L terminal on the CS alternator, and you must wire a resistor in series with the wire, and the alternator. The resistor value is recommended at 85 ohms, 5 watts, but I know that guys have used up to 300 ohms and .5 watts with success.


The red lead from the EVR should go to the S terminal on the CS alternator

and I recommend using a no. 10 or no. 8 gauge wire from the alternator to feed the main junction.

Are you still using the stock battery gauge in the dash cluster or have you converted to a voltmeter?

[MARKDTN]

If it is a CS130, do yourself a favor and upgrade to a CS144. Much less problems. Same wiring as a CS130, just plug and play.