Hi,
I've had the following happen twice. All instruments, tach, fuel gauge, turn signals (try to flash but don't, charge light dimmed), parking brake light will stop working and the Charge light will come on, but the plugin lighter outlet meter shows 13.7 to 14.2, however the hazard flashers work, truck runs and starts normal, turn signals seemed like not enough power because the charge light dims. The first time it happened, I plugged and unplugged all the relays and alternator plug as well as the round connector and all came back on and worked fine for about 2 months.
The second time, this didn't work. What did work was while the truck was running, removing the positive terminal five consecutive times while running each time with different results until it seemed to 'clear up' on its own. The first time I removed the terminal the truck stopped running. The second time it remained running but the charge light was still on. The third time the parking brake light came on, tach and gas gauge all came on and the charge light didn't, but as soon as I used the turn signal the charge light came back on. Repeated these steps one more time and all was well and remains working fine, even after multiple restarts, very strange....! Driven daily, and just trying to avoid a possible future tow bill....