JZA80: Fix broken tail indicator after upgrading rear lights
LAMP FAILURE INDICATION PROBLEM FIX ( AFTER INSTALLING NEWER ’97-’98 TAILLIGHTS ON OLDER ’93-’96 SUPRA’S ):
In order to fix the problem, you need to locate the lamp failure sensor box which is in the rear quarter panel on the driver’s side ( behind the panel with the rear hatch area light). It’s a small rectangular purple in color electrical box which is clipped in the panel from the inside pocket with just the purple clip showing protruding the panel.
Unplug the wire harness from the box and then take the backplate off with a small screwdriver to expose the electrical board.
This next step is a little difficult and have to be very careful not to mess the electrical board up and the electrical pins. Gently try to get the electrical board out of the plastic box container without tweaking the pins. Once you can get the electrical board out of the container flip it to the side with the integrated chip and the two resistors that are suspended & soldered to vertical posts.
Part numbers are:
(273-5.1k) for the 5.1k resistor
(273-30k) for the 30k resistor
The higher value resistor (30k) goes closest to the black integrated chip. The lesser value resistor (5.1k) is the one that will be furthest from the black integrated chip.
Once that is done, it would be best to touch up all the solder joints on the backside of the electrical board just to ensure all the connections are soldered and the pins are solid connection. Then test the board by plugging the wire harness to the electrical board and turn on headlight switch fully and to ensure lamp failure indication in dash is not lit. Then to test it, unplug a taillight bulb from its socket, the lamp failure indication should light up like normal. If it does this, the problem is fixed and you can reassemble the electrical board back in its plastic box and put the car back together and your done. No more annoying warning light up in the dash when you have your lights on unless of course you blow another bulb out.