In the 86, yes. A yellow wire comes from the relay socket, changes to an orange wire and enters the instrument cluster via the round multi-pin connector on the rear of the cluster.
On the Left side of the Overdrive behind the trans with two wires sticking out. DIY with a special wrench that allows clearance between the body tunnel and the side of the Overdrive unit.
But why replace the solenoid? Was the overdrive working before you installed the tach? If so, then your problem is with something that happened when you had the cluster out to install the tach.
If it was not working prior to the tach install, something else is most likely the problem. A blown or corroded fuse, a bad 4th gear switch on the trans, loose or dirty terminals.
Where your problem with the non working OD depends upon how the dash light reacted to the button on the shifter.
If the dash light came on with the push of the button, and no OD, concentrate on the terminals and connections to the solenoid. The wires have a tendency to break inside the wire right at the terminal crimp and not separate at the insulation.
If no dash light with the button push, the fuse, or the 4th gear switch on the top right side of the trans.
Duane
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.