Unsuccessful troubleshooting for driver's rear tail light
 

My driver's rear tail light is out. Both hazzard/turn and brake lights work - but I can't get the parking/tail lamp working.

• Swapped bulbs with passenger's tail light - problem remains on driver's tail light.
• Swapped "adapter" (plugs between harness and bulb) with passenger's tail light - problem remains on driver's tail light.
• When activated, I get 12V across hazzard/turn wires (green/orange = hot, black = ground) regardless if a bulb is installed or not.
• When activated, I get 12V across parking/tail wires (brown = hot, black = ground) ONLY if a bulb is NOT installed. As soon as I install a bulb, voltage drops to 0.

So... I know that the bulb is working and the "adapter" is working, but there has to be a short somewhere in the system. It got dark out, but tomorrow I'm going to try to bypass the "adapter".


Any other suggestions or advice would be appreciated.

Actually you do not know that the bulb socket is working.

If you are installing the bulb correctly, and the voltage is lost, something is wrong with the bulb connector.

with the bulb out, the socket tests correct for the parking lamps, it should work with the bulb installed. If not the issue is with the bulb connector.

if there was a short ( or more correct an open ) in the system, the bulb connector would not have +12 on it without the bulb installed.

Thanks SSCULLY.

However, when I move the bulb connector over to the passenger side light, it works. The only thing that remains constant is the driver's side harness - so I'm thinking that's the culprit. I'd like to get the Ford OEM replacement harness, but not at $100+. I'm going to look at AutoZone or NAPA for an aftermarket harness that I can splice in.


So we're talking about the same parts, here's what I'm referring to as "harness" and "connector adapter".

http://i480.photobucket.com/albums/r...827-0923-1.jpg