Brake and turn signals

If all these symptoms are related and started acting up at the same time, forget the flasher. That has nothing to do with the brake lights. Instead, you need to look for things all those systems have in common. The best suspect is the ground circuit for all of those lights. Also, I assume you mean the back-up lights turn on when they are not supposed to be on. That is another important clue. When lights operate at the wrong time, the ground circuit is usually involved in the defect.

Start by inspecting the wiring harness. The ground wire will be bolted to the body someplace near those lights. Look for a terminal that is corroded off or the wire is broken. If you do not find anything visually, you will need a voltmeter, and I will look up a wiring diagram and tell you where to take the measurements.

Did you do the visual inspection? Did you find a broken wire?

Please be specific. Which switch are you turning on? Exactly which lights are turning on? Are you saying some lights turn on just by replacing the brake light switch, even when the brake pedal isn't pressed?

I was hoping to solve this sooner. I'll be out of town at the Iola Old Car Show swap meet until Saturday night, so don't panic if I don't get back to you right away. Internet access is real poor there because over 100,000 people are trying to use it at night.

I can't find any reference to an automatic transmission for this model. All my diagrams are for a manual transmission. The second pair of wires on the brake light switch is for the cruise control. It shows a dark green / red and a pink wire for that function.

The brake light part of the circuit uses an orange wire for the 12 volt feed, and a brown wire. I think where I would start, since you already found a melted wire, is to unplug the brake light switch, then use a stretched-out paper clip to connect the brown and orange wires together in the connector. Doing that should turn on the brake lights, even with the ignition switch off. Check if that function works. Also check if that makes any front bulbs turn on.

If everything looks right so far, turn the ignition switch on, then see if the signal lights work properly. If they do not, remove the "Backup Lamp" fuse, number 5, a ten-amp, then see what happens. That feeds the pink wire to the brake light switch. If things change with that fuse removed, that pink wire would have to be melted to the point of touching one of the brake switch wires.

The even better suspect is still a bad ground in the rear. Remove the paper clip from the brake light switch, and leave that switch unplugged. Now see what the signals do. The rear signals and the brake lights are different bulbs and are not related to each other, ... Except that the left brake light bulb and all the tail lights share a common ground point.

Actually, I'm going to have to stop here until you update on what you find this far. The wiring diagram is real confusing. According to it, you do not have a right tail lamp or left or right brake lights! I'm guessing that is not true. Also, tell me exactly how many bulbs you have in one rear lamp assembly, and if you can figure out if the stop lamp filament is the same one that's used for the signal. The diagram shows them as two totally different bulbs, but I'm not sure if that's right.