Since I got inquiries about the Front Diff Lock (FDL) indicator, here it is.
The FDL indicator is to the right of the RDL indicator which is to the right of the CDL. From left to right - CDL, RDL, FDL.
I have installed a ~75psi Normally Opened pressure switch downstream of the FDL activation solenoid. One lead of this solenoid goes to ground and the other to the indicator. Since the indicator gets power with the Ignition, when the solenoid opens the pressure switch closes and the indicator get ground and lights up. This scheme gives you assurance the locker did get the activation air pressure, and if the locker did not mechanically failed, the front axle is locked. It is not as “closed loop” as the Toyota system but it’s better then the ARB wiring that just shows FDL “switch on”.
I soldered a small gauge wire to the PCB where the connector is soldered to the PCB. The picture shows the pin on a 1999 TLC instrument cluster. I think the bulb was there. The bulb was not there for the spare tire carrier ajar, which I also wired…. Or it’s the other way around… can’t remember.
I hope this helps.
Doron.