I copied this from an earlier question:
What could be wrong with brake lights, if not the switch, bulbs, or fuses?
The brake lights have stopped working in my Ford Explorer. The bulbs are new, the brake switch is new, the fuses are not blown. What else is there to check?
by Paul @ Bundy's Auto (becker@ThisisToPreventSpam-VKW-RemoveThis.wzrd.com) contributed on November 08, 2003, at 7:26pm. Last updated on November 10, 2003, at 12:26pm. Sounds like you've been doing some guessing! You need to find where the power stops. Use a test light at the sockets. If no power, go to the wire to the socket. When you find where power goes in but doesn't come out, you have your answer. Assuming there is one answer. There is also a possibility of a ground problem. Good luck.
It could be one of many possibilities. I had a brand new s-10 that I was working on and it would blow out the fuse at weird times. I ended up chasing it down to a bolt that was left under the carpet from the factory. the bolt had rubbed through the wire and would short out and pop the fuse.. sometimes electrical problems can be a bear......
A car that shuts off when the turn signal is used indicates a major short in the electrical system. When the turn signal is used, it cause a massive draw on the power and shuts it down.
A short in the turn signal switch or the wire in the steering column is shorted. There is more likely a short in one of the bulbs. easy to find remove bulbs until the bad one is found then replace
A short in either the multifunction turn signal switch or a short in the wiring harness going to the switch.
The turn signal relay is underneath the dashboard on the drivers side in the fuse box. If you are looking for the acutal turn signal its on the steering column.
short circuits in the turn signal and brake light circuits
Could be there is a short to ground somewhere in the system or the circuit is overloaded with extras. If you have a trailer plug in back take a good look at that area for a short.
To replace a turn signal switch in a 1993 Chevy Lumina go to the trunk of the vehicle and find the plastic covering for the turn signal. Remove the cover and replace the bulb.
There is a short in the wires in the turn signal circuit. The combination switch in the steering column is a good place to check. Do the hazard lights still flash?
A short in the turn signal wiring can cause the voltage gauge to fluctuate. A loose ground wire can also cause the gauge to fluctuate.
When replacing the rear turn signal on a 1999 Acura Integra open the trunk. Locate the rear turn signal housings and find the bulbs. Remove and replace the bulbs.
Yes - on passenger side of dash with turn signal and emergency flasher relays. Turn on your turn signal or e-flasher and listen for ticking - you'll find it...
it's normally under the dash.. turn on the turn signal and find the device that is clicking. That shoudl be the flasher unit/regulator/relay