Tail lights not working

Hi Alex. Thanks for the quick response and the schematic! I'll investigate further when I get home tonight and let you know what I find. From the schematic, it seems that a faulty taillight assembly ground would also prevent the stop/turn function from operating, but those are working correctly.

Hi Steve. Thanks for the response! The plate lamps and markers also do not work. Thanks to the schematic you guys provided, I was able to determine that power is not going to the tail lights. Power is going to the stop/turn lights when brakes or turn signals are activated. The only constant power at the light plug is apparently for the tail lamp outage detection signal. I haven't found any fuses or relays that don't work. But the park lamp relay doesn't seem to be pulling in. It doesn't click when the lights are turned on but by swapping it with the fog lamp relay I verified that is an issue with the circuit and not the relay. Both worked (and clicked) in the fog lamp relay socket, neither worked in the park lamp socket. There is power to the socket corresponding to terminal 85 of the park lamp relay but there seems to be an open circuit in the line to the socket corresponding to terminal 86. I'm guessing, but don't know, that there's a relay, switch, or something that's supposed to ground terminal 86 of the relay which then pulls in to connect terminals 30 and 87. Both the "LT PRK" and "RT PRK" fuses in the under-hood fuse block are okay.

I really appreciate your help! I'm out of ideas and, although I hate to admit defeat, I need the car back on the road and will drop it at the dealer in the morning.

Hi Steve. I determined that the relay worked fine but that there seemed to be an open circuit that would not complete the path to pull in the relay. So I took it to the dealer this morning. They traced the open circuit to corroded terminals in the under-hood fuse block. According to the invoice, they replaced terminals for circuits 1080, 32, 143, 5126. Everything works now. Labor of nearly $490.00 plus parts and shop supplies brought the whole bill to over $550.00. But at least it's safe now and back on the road before the snow hits. Thanks for your help, I really appreciate it! You guys perform a great service and do it very well!