2000 Cadillac Seville Alternator Compatibility

Old alternator tested. No voltage output Yes tested at battery around with smart charger And with battery unhooked tested with multivoltmeter 11.7. Same as jump terminal under hood and in dash It doesn't change with a load or not Old alternator said baterry not charging in dash

Ok there's a orange wire that has around 12 v. Red wire has nothing. And a tan wire that had nothing and this is with switch on engine off while plugged into alternator the big red wire also had volts battery was dead so had charger hooked to battery

Ok been waiting all day for response. Pls help lol

It's an sls. So the big red wire runs from alternator and charges battery. Do the wires on the plug all run into alternator? When u say small red wire has power. Wat an I looking for it to read on my meter? The grey should not nothing until a call for charge?

And the orange one?

Well I have been more confused than ever I traced the best I could the small red wire from plug to brain not finding anything with that wire I did find a plug unplugged that was located behind an engine mount that I believe to have been unplugged for sometime but I'm not sure I believe it to have been from were I had mount replaced a couple years back not sure Wat it went to possibly oil pressure or something. After checking it did not appear to have changed anything in readings. The next day after corresponding with you more about Wat the wires should have on them and were they came from. I had unplugged plug checking from plug end unplugged as well wires from plug with plugged up. And after plugging back in then suddenly what I am getting has all changed. Now insteAd of low voltage on dash it's high voltage but only on dash. When first cracking car it says battery not charging service system. And after a bit the light will come on tthem it will show 16.4 voltage hi and will after a minute settle to 13.5 swing voltage ok With car running putting a load on system it will drop to as low as 11.8 and when you take load off it then will go back up to 16.4 on dash but will stay co stand at battery with volt meter at 13.5 and at dash will after a few seconds to a minute will on dad will settle back to 13.5 and say ok. But light will stay on throughout. I have discovered a possible cause but altrnator will have to taken off to know witch is were the plug plugs to alternator a potion of the female side is missing its tge cup part with wat the clip clips on to hold tight. Cant see what or how much is broken from there can see all prongs are still there and it is tight when pluggen but im thinking if cracked on up into reguator hausing this coukd cause all of weid readings other than the fact that when checking wires while in run position and engine off with plug plugged or unplugged in not getting nothing but mv at harness on any of wires at the fuse for orate wire if I am on the right fuse 'PCM batt'. If remember correctly I'm get voltage at fuse the large red wire has voltage but only 8-9 volts All this has me confused as I possibly can be. Ive already contacted online salvage yard to see about another alternator even if not causing problems it needs to be able to clip to stay tight. As far as any of the other readings I don't have a clue I am going to put new batteries in my multimeter and check everything again though I don't think it's reading incorrectly No low battery signal as well as I used it to check some 1.5 volt batteries and it worked fine. I realize this is alot of info and your probably wondering wats up with me and the car but so you know I am too at this point. I appreciate you hep and feedback. Thanks. Todd