When I put the brakes on the right brake light is intermittent and the left rear reverse light comes on. When I put the car in reverse, the rear backup lights work (whew). When I turn the left turn signal on, all the rear lights blink, alternating side to side. What a clusterf***

 

Godspeed to sorting it out.

 

^ great advice


If I were you, I'd pull all the bulbs out of both tail light assemblies and visually check all the bulbs. Replace the bulbs even if they look questionable. Can't tell you how many bulbs I've replaced that looked fine but actually weren't. For the time being, leave the reverse bulbs out and install new turn signal bulbs. Check turn signals to see if they are properly functioning. If they do, then install new reverse light bulbs and check again. Let us know what happens.

 

The key to your issue is the report of alternating blinking. Look for a ground connection that has developed corrosion or broken loose. Do you have a 12 volt test light? I find that is usually better than a meter for sorting this kind of stuff because it applies a small load to the circuit that a meter does not.

Even if you are not an "electrical guy" this will not usually be too hard to figure out with a little logical troubleshooting. Get the schematic printed out and get the test lamp ($3.99 Harbor Freight) and the group will walk you through it.

http://www.harborfreight.com/circuit-tester-30779.html

 

Discovered the cause of my problems and immense frustration. It needs a new right rear light module. Purchased a used one from JustParts.com for $47 (incl shipping)

 

What went wrong with it? A broken solder ribbon? Maybe it can be fixed by desoldering some of the connectors or pulling the positive tabs out to better seat the bulbs?

I saw one of those for sale on eBay a few weeks back. Not too expensive.

 

I finally resolved my taillight issues. It required a new pass side bulb holder, and three new bulbs. Whoever changed the bulbs before I bought the car had wrong bulbs installed. Geez...

 

Glad you found it.

Not to whip a dead horse, but to help with electrical diagnostics and troubleshooting, the internal problem in your bub module is almost certainly a ground burned loose. That is indicated by the turning off and on of one circuit resulting in the opposite effect on another. The different loads on the circuits cause the ground point to go high and low in voltage.