I have a 97 SLT with a problem. the left turn signal, and tail light are acting crazy. the turn signal blinks rapidly like a bulb is out but all the bulbs are good. when the brake pedal is depressed, the left side parking light comes on. (dimmer than the right side} with the headlights switch in the parking or on position, the parking light is on but goes off when the break pedal is depressed. i replace the turn signal/wiper control switch but no change in the trouble. has anyone ran into this before? and where can I find a wiring diagram for the circuit? thanks for reading....

 

You have a bad ground somewhere causing a back feed which could very well give you false light out symptoms

If I'm thinking correctly its the ground for the left brake light (probably shared by the taillight), as the ground is searching its going down the brake light ground back up the left taillight ground through the bulb and into the hot side now find a ground wherever the running light circuit goes, causing bulbs to light up in the process that shouldn't be normally, but dimmer because some voltage is being lost

 

thanks, I'll follow up on that.