Reverse lights on with not in revers and off in reverse

[AtomChurch]

The reverse lights worked I didn't have a problem with them at all. Now they are on when the car is on and off when in reverse. The opposite of what they are supposed to do. Could this be a failed switch? because it doesn't sound like one to me, whenever any of my other switches go out they are always stuck either on or off.

 

What could the problem be?

[DanielC]

I am not exactly sure about the reverse lights on a 510, but on a 521, there is a switch on the transmission that has power applied to it when the key is on, and the switch is only closed when the transmission is in reverse, and then the reverse lights come on.

There are also additional switches on the transmission that are used for pollution control that are on at different times. One might be on when ever you are in neutral, another is only on in third gear. It sounds like you have your reverse light wires hooked up to the wrong transmission switch.

Also check the grounds for the taillight assembly. A lot of weird wacky problems can happen when the grounds are bad, because sometimes some lights on the taillight assembly ground through other lights, and cause the wrong light to come on, or more than one light will come on dimly.

Make sure you have a good wire ground from the alternator to the engine block. Make sure the wire from the alternator to the voltage regulator is good. Make sure the battery grounds to the engine block. Make sure the engine block grounds to the body of the car, and if you have a truck with a frame, that also has to ground good to the alternator, and the battery.