6.2 chevy charging problem

[Alegro88]

Dear All
My allegro 1988 6.2l diesel
When started the charge seems ok but whilst running the charge drops to almost 8volts. It doesnt charge the battery but it does still run ok which is strange as i would expect it to stop if just running on the battery?
I then need to use the rear generator to charge the battery and start it again
Any advice freatly recieved.

Chris

 

[PeteH]

Lack of charge

Hi

How are you measuring the output? You really need a good Digital multimeter across the Alternator to a good "earth", a charge of less than "Battery Voltage" (nominally 12v) would indicate an alternator problem. a "good" alternator will produce 13 to 15 Volts dependant of battery state. If it`s the same configuration as my pace arrow was (6.2 diesel) the "fan" belt also drives the Air-Con. and was prone to slip badly reducing the alternator speed. and could part company without loss of other functions (P.A.S) etc which had separate belt(s). One indication of a broken belt is a light on the dash (poss Orange or red) when the engine is running.

pete