Join Date: Mar 2002
Location: Austin, TX, USA
Re: 67 camaro Charging
The field windings are always polorized the same way. So after a while, the armature will develop some residual magnatism that will make the alternator put out but not enough to do any good. But there are other possibilities here.
First, verify your ground is good. With the engine running, check the voltage between the alternator shell and the negative battery post. Should be a very small reading of less than 0.1 volt I'd say.
Can you tell us what style of alternator it is? Is it a 10 or 12SI style, or perhaps a CS130 style? The wiring of each is a bit different. In the case of the CS130, for example, ther should be plastic weather-pak connector on the side with 4 or 5 wires coming out of it. The brown wire is the gen lamp / exciter line, the red wire can either be connected to the B+ terminal or a remote location for remote voltage sensing. If the red wire isn't hooked up you'll have the problem you described. Then of course, there is the big red wire connecting to the battery junction block.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI