My wife's 1993 Mercury Cougar XR-7 has been having turn signal and brake light issues. Sometimes they work and sometimes they don't. I've replaced the side signal switch,Column Switch or turn signal switch as I call it. It's also called a Multifunctional Switch. The tune up shop also changed the thermal switch under the dash. I took her car for a test drive after replacing the turn signal switch and it worked for about 2 minutes and quit working again. What happens is the turn signals quit working inside and outside of the car. The rear window brake light still works and the right side brake light also works. All the fuses are good. One of the shops told me that if the rear window brake light is on and working when the turn signals don't work, it's the thermal switch. OK, so I tried that! Put the new switch in and it didn't work so I put the old one back in and it worked just fine. About 10 minutes later the signal light and brake lights quit working again. I have no where to go from here. The shops want to replace the whole steering column now for big $$$. Any help would be greatly appreciated here!
you're going to need to check your wiring when the problem exists. make sure you have power going into the turn signal flasher. then see if you have the power coming out to the turn signal switch and the out from the turn switch. you have to figure out where you are losing the power at. Make sure the flasher has a good ground connection to it. look at the diagram and follow the powers through the circuit.