Hi all I just joined the group and am working on a manual 2001 sl2 as a fun car to commute to work. I have learned a lot about Saturns getting it running but there are a couple issues I cannot seam to resolve. The primary one is a battery drain that I tracked down to the alternator. I am getting voltage when the ignition is off. Being a 2001 there is just one wire(besides the 6 gage going to the starter) going to the four prong plug on alternator. Both the battery and alternator are brand new(the voltage loss was the same prior to the new battry and starter). Looking at wiring diagrams this brown wire from the alternator comes straight from the pcm. My first thought was that maybe the ignition was bad but removing the fuses to the ignition one by one did nothing to the voltage the alternator was getting. The one fuse that did finally cut the voltage drain was PCM b under the hood. Could this be a bad pcm?? It seems like such rare failure I cannot find any issues online like it and it seems the pcm is never the issue but I don’t know what else to make of it. Can a bad gage cluster cause this? I don’t know if this is helpful but my speedometer is not working. Any help is appreciated. Thank you

 

https://charm.li/Saturn/2001/SL2%20L...nd%20Charging/

 

thank you this is an awesome reference tool I will try some of the suggested testing tonight!

 

If you have drain and it stops when you remove disconnect it means the alternator is shorted internally.
If the PCM is not going to sleep you should flash it with the latest software. Even if it's up to date go through the setup.
If it sill won't sleep it's bad.

 

when you say flash the pcm is that something I can do from a scan tool from AutoZone or is there some specialized tool I need to do that? I have been thinking I might have gotten a bad alternator from AutoZone but really did not want to run through the hassle of pulling and swapping it unless I really needed to. I am also having issues with the speedometer, odometer, and oil sensor not working despite replacing the vss, and the oil pressure sensor

 

Does the drain stop when you disconnect the alt?

 

if you disconnect the (I think brown?) Wire coming off the wiring harness from the pcm it stops. You can hear it humming and stop when you pull plug. I did not have to disconnect the fuseable link to the starter to get it stop the drain.

 

Show me on the wiring diagram.

 

 

https://charm.li/Saturn/2001/SL2%20L...ing%20Systems/