Now.. not knowing what erratic is to you, but with personal experience, you very well could have a cracked head gasket, or you could need a new water pump, or your thermostat could be in need of replacement.
Simple, just replace your alternator..
where is the diagram on a alternator belt ..huh?
what wires do i need to hook up to the alternator
The Volatge Regulator Is Inside The Alternator.
The 1996 Oldsmobile Cutlass Supreme temperature sending unit can be found on the front of the engine. The temperature sending unit will be a few inches above the thermostat housing.
go to your local auto parts store and ask for it.
replace the alternator if your system isn't charging.
If your battery was dead and you jumped it to get it started and the gauge shows your not charging you need to replace the alternator.
the alternator is located on the upper left hand side of the engine. just follow the belt and you will find it located at the top.that is where mine is.
Depends if it is the 3.1 or 3.4. I have a 3.4L and I let the dealer do it. The car had to be raised and the engine lowered since the alternator is located on the rear of the engine towards the bottom. See question regarding the 1995 Cutlass Supreme . Same applies unless you have the 3.4 version of engine.
It's inside the alternator, most people just replace the alternator if it isn't charging but you can take the alternator apart if you know how and put in a new voltage regulator for about $15.
Stick the starter in the cutlass supreme.