97 sport 4x4 not charging?

Went out today and had little to no battery life. ( NO TURN OVER) So went and grabbed a new battery as the old won was three years old. Well that's all fine but the Amp meter on dash is not going up its going down as the days use of the vehicle went on. So im thinking bad alternator maybe. But is there a way to test for true output from this alternator? Tapping the battery posts seems a little in accurate as there will be voltage at the battery. Not a lot of currant but voltage. Is there a fuse to the charging system in this thing? Should I just go down and grab a new 130 amp alternator and through it in?. What's your advise folks?

Oh! And what's the 4.0 "VIN E" AND "VIN X" MEAN. I get the 4.0 L block. But the VIN E And VIN X ????? I am asked this online when looking up the Alternator price.


Thanks

\Jeff in Seattle.


Thanks
jtherrmann@comcast.net

E......4.0 L EFI SOHC, 207-210HP
X......4.0 L EFI (push rod),160HP

Check for supplied battery/current at the large lug (Black/Orange) on the alternator.. There are 2  fuse links inline from the starter relay/solenoid for current to alternator, but if current is present they should be good.. Also, fuse position #6/15 Amp in the Power Distribution Box..

Some parts stores will check an alternator for free if you take it in to them. If you have the old one it's also easier to check to make sure the new one is the same.

 Your VIN number just tells you which power output your alternator should be. If you take the old 1 with you should be sure to get the right one (some have the output marked on the alternator anyhow).

Thanks Guys!
Its all good. It was the Alt. I as well did the Plugs - wires , Belt, Air filter, and pulled the Air mass Vlave off and cleaned it while i was in there. All is good now.