Brake lights and turn signal - One side only

**tomc** · 03-23-2017

My brake light and turn signal on the rear drivers side have gone out. Turn signal lamp in the car and front turn signal blinks rapidly. I have replaced the rear bulbs and no change. I have power to the sockets because the normal tail lights are all OK.

Based on everything I've read, I'm leaning toward the multi-function switch. Anyone have any quick test to see if this may be the culprit?

**Scottydoggs** · 03-23-2017

check the bulb socket well, those tails tend to let water in and over time the socket can corrode. that rapid front blinking is what happens when the rear bulb is not seen.

**tomc** · 03-23-2017

They look pretty good but I'll check them again. Results tomorrow.

**Scottydoggs** · 03-23-2017

i forget id they are the 3057 bulbs or not, but the push in type the metal bar inside the socket can break, when it does it can break the wire on the bulbs push tab or leave marks on the plastic. had this issue with a front parking and blinker bulb socket, chased it for a while.

**tomc** · 03-24-2017

Checked all the sockets, cleaned well and added dielectric grease. No change. In addition, service engine light came on this morning. Haven't had a chance to check it yet.

Another day in the life of a 17 year old GTP owner.

**mguzzo** · 03-24-2017

here's something to check: pull off the passenger tail light assy and check the condition of the wiring on the pass through out of the trunk. There's a bulkhead connector that is all potted up. On my old coupe, my brake lights and turn signals were acting funny. The wires on the bulkhead connector were corroding to the point where I had a sneak circuit, I would step on the brake and the voltage would come back up through the tail light circuit, through the headlight switch, and turn on the fog lamps! I ended up cutting and splicing the wires on the whole taillight / brake wiring harness.

Take the dielectric grease off, that's OK for high frequency / high voltage (spark plugs) but at 12 volts DC it's an insulator.

**tomc** · 03-24-2017

Already had the bulkhead connector and everything looks to be in good shape. Maybe dielectric grease is the wrong terminology. I had a packet of grease that said "Light Bulb Grease".

Looking at the wiring diagram, there is a yellow wire coming straight form the multifunction switch to the left tail / stop / turn lamp. I will check the voltage in at this point with the turn signal on. Seems like if there is no voltage here the multifunction switch would be the likely culprit.