ok, my cryptic. there are only about 400 variations of I/O
with about 5 manufacturers
however.....generic instructions.......follow the voltage path
from the battery negative, the cable goes to the engine block. from the engine block the cable goes to the ground terminal buss and thru the wiring harness to a few splices....... how are those connections
from the battery positive, the cable goes to the B terminal on the starter. from there there is a cable up to the large circuit breaker or on some 3.0 liter installations, a large fuse. from the large circuit breaker or fuse, the voltage goes to the big connection in the harness. from there it goes to at least 2 connections prior to the key switch B terminal. this is the red wire. once the key is on, the voltage goes thru the key switch to the I terminal. from there, it energizes the dash, it also goes back thru the two connections back to the big connector at the motor. from there it is spliced off to feed the ignition, coil and a few other things. this is the purple wire
when you turn the gauge to start, the ignition switch energizes the S terminal on the switch, which goes thru the neutral safety switch at the controlls, then thru the two connections in the harness to the big plug, then to the starter slave relay. from there to the S terminal on the starter. this is the yellow wire with a red stripe.
so where is there voltage
and where is there not voltage?
if you havent done so, clean your connections.
