hLARP7

Hello old sube folk! I have revived an old project car of mine. For completeness, the car is an pre update 87 XT turbo FWD 5 spd. When I started it up for the first time it ran fine and all the dash lights and instrument bars worked great. I have since started gutting it and cleaning the mouse homes and filth from the car. After a really good rain I went out to move it and it started up (but died once) just fine but the instruments were off and the ECS light came on. The warning lights on the instrument panel still work and it still lights up. I have plugged back in everything that was removed in cleaning besides the center harness (hvac fan, temp, ect) I have done some reasonable searching but can't find details on how to determine what the ECS is on for on this specific car. Does anyone have any ideas or have guidance / resources they would be willing to share? Thanks!