big volts

further underhood checking. I havn't had time or energy to pull the instrument cluster out to check wiring in there. but this is what i'm finding ub=nder hood now. the volts where the fusbilbe link wire goes to bulkhead reads 12.4 same as batt +, starter relay stud, and alt stud ( actually 12.2)....... the big hot wire coming out of bulkhead was reading 16.8-17.5....... from what I read from you guys this should be 12.4 ???????????
all this is at slow IDLE

o k..... the green an blue wires at the alt show 8.0 ands 11.4...

I pull the wires off and check at V R....... green 14.4 and the BLUE again I s bouncing all around 1 to 19 ............. this is not normal from what I read here????????????

earlier I couldn't get a rading at the blue V R wire. I have to really rub the probe there hard to get a reading and like I say it bounces from 1 to 19...............

so 2 questions: should not I have the same volts in and out of the bulkhead????? what causes this????????????

and this blue wire at VR bouncing all around from 1 to 19 V? bad connection, new new??????

thanks for the help!