Check fuse 7 (15 amp) under the left side of the dash. If the fuse is good, the problem is in the rear electronic module. The two back-up lights are individually controlled by this module. The module is behind the panel at the right rear of the vehicle. The white/yellow wire (terminal 10) goes to the right rear lamp and the dark green/orange wire (terminal 9) goes to the left lamp. Now the good news. The rear electronic module gets the signal to turn the lamps on from the powertrain control module. Unless the fuse is bad, this may be more than you can deal with. Take it to Ford or another mechanic that understands the programming involved. Carl
Check the circuitry to the backup lights. The same fused circuit is probably used for both brake lights and backup lights. As you go past Reverse, the backup light probably is turned on briefly, causing the fuse to blow. It's just a thought, but I'd think it worth checking.
Bad bulbs can be the cause of your reverse lights not working on your 1999 Toyota Tacoma. A problem with the reverse switch or bad wires can also be the cause of your reverse lights not working.
Having it on "PARKING"
Blown fuse or defective brake light switch.
head lights won't work, no power to them, signal works , reverse lights work
Backup Lights do not workThe backup lights are on a separate circuit from the brake lights and each use a separate dedicated switch to control when each group of lights turn on and off.The type and location of the backup light switch depends on the make, model, and year of production of a vehicle, and since I'm not familiar with your vehicle, this answer of necessity will be generic in nature.The backup light switch is usually mounted either within the dashboard or, in the engine compartment. In either case, it will be mounted directly adjacent to a moving part of the gear shift mechanism. Thus when the transmission is shifted into reverse, the moving linkage will move the switch, turning the backup lights on.However, on many later model vehicles, the backup light switch may be mounted by screwing into the side of the transmission so that when the transmission is shifted into reverse, the backup lights are turned on.In the case of the switch mounted in the dashboard area or engine compartment and working off of the movement of the transmission shift linkage, the cause of failure to operate could be:Switch is not properly adjusted [very common].A connector or wire in the circuit has become disconnected, cut or broken [slightly less common].The switch itself could be defective [not very common].These same causes are true for brake light switches mounted into the side of a transmission, except that I'm not aware of them being adjustable and thus if the switch is the cause it's defective and replacement of the switch is required.
Reverse light switch bad or out of adjustment.
Did you check the light bulbs? If OK, probably a bad reverse light switch in tranny.
There is a switch on the shifter or trans that turns on the lights when the vehicle is placed in reverse, it is out of adjustment or faulty. And don't forget the bulbs or fuses as a cause.
the most common thing is a faulty multifunction switch.
possible electric system short
battery is low or almost dead