| Re: 86-89 Digital Instrument Cluster "OD" light |
Subject: Re: 86-89 Digital Instrument Cluster "OD" light by CentralCoaster on 2012/12/12 21:32:27 I'm looking at the 86 ECM wiring right now... looks like you are right. The ECM connects to the dash for serial data and speedo. Everything else is fed from other systems. The ECM via the overdrive relay, sends the OD command to ALDL pin F, but not the cluster. Also, it does not receive any inputs from the gear switches. So all the determining of when to trigger those dash lights must be through the serial data, and calculated based on speed and rpm. This makes sense as they got rid of those switches through the years. In 85, the first gear switch did communicate with the ECM. |
