Intermittent short? Ignition switch? Turn signal switch?! I'm stumped!

[440STRKR]

Hey guys... Here is my goofy Intermittant electrical issue. Any input would be extremely appreciated. Please Note: my turn signals work occasionally, running lights work, i have never had brake lights though (i am getting power to them though). Firstly When my head unit power wire touches the relay and battery is attached I get a horrible spark (this makes me think my radio is shorting something out). Secondly my turn signals are very slow and sometimes stay on continuously instead of blinking... Not a strong blink at all. Also sometimes when i shift to reverse or hit the turn signal the radio resets... Earlier today I disconnected the positive going to my radio and taped it up. Started the car with a full charge optima. Let her warm up and shifted reverse. Instead of the radio turning off the car cut out immediately. Shifted back to park and tried to restart the car, turned the ignition and nothing, no clicks , nothing. Got angry and went inside came out 2 hours later and car started fine. Ran fine. Turn signals worked great. Brakes lights still don't work, running lights still work. No problems shifting. So I'm thinking that the problem lies in either the turn signal switch, ignition switch or a short. Thanks a lot guys

Cheers

Ray

[Chryco Psycho]

start checking all the power connections notorious ones are the firewall bulkhead plug column plug & the ammeter connections .
you say the brake lights have power but where , ino tthe turn signal switch , at the rear bulbs?

[Jamiez]

For the turn signals sometimes working/sometimes not, that sounds like it might be the flasher.  It's a small cylinder shaped object (about 1/2 the height of a D battery) with 2 electrical connections.  The car should have 2 of them...one for the hazards and 1 for the turn signals.  I believe the turn signals are mounted next to the ash tray and the hazards are mounted to the steering column, but it's been a while and I might have those swapped.

All the rear lights get power from a harness that connects to the main harness behind the driver's kick panel.  This is also how the dome light and fuel sending unit connect in.  For the brake lights, you can remove the bulbs and the cans have 2 pins, one is brake, the other is the parking. You should have close to 12V between the pin and ground, less voltage means the lights will be dim.  The ground is most likely the problem as the light buckets ground to the lens housings which then ground to the body.  Corrosion or similar  obstructions may be interrupting this circuit.