I put a new alternator and starter on my 97 dissel 12 vavle and here lately the alternator gauge drops real low and then my idle drops down and so does my oil pressure...if i rev the engine up to about 900 rpms then the alternator starts charging again and will stay up until i stop the truck and start it agian and it will do the same thing....does it mostly when the weather is really hot...also want to know if someone knows what the idle should in park and then in drive...mine in park is about 5 to 6 hundred and when in gear it is about 4oo rpms...any help will be appreaciated

 

Not sure how much info you have on the charging system ,
The regulator is in the computer , very rarely goes bad , most of the time its an external wiring connection issue , thats beside batteries .
It sounds like your idle is just too low , just going by [ bad ] memory , in drive , ac on , it should be 850 RPM .
Some have a lower idle preference and that works in non winter climates , the eng may stall with a cold eng at cold temps [ below about 30 * F ]

 

Try this first.
Idle adjustment:
http://www.dodgeram.org/tech/dsl/adj...d_Gen-Idle.htm

Chris

 

thanks i will try to turn the idle up and see from there