[onZedge]

Here's something to try:

I just had my console and cluster gauge out to do some wiring modifications (and clean a bunch of connector contacts with Caig DeoxIT D100L). When I reconnected the cluster gauge to the harness, I turned on the ignition switch on just to verify the charge light was on - AND IT WASN'T!!

The little socket (that holds the charge light bulb) plugs into the back of he cluster and rotates to lock. Well, I had to rotate the socket to somewhere in between "full lock" and "full unlock" to get the charge light to come on reliably.

Perhaps this is the same issue that caused the PO to bypass the blue wire in the fist place?