Question on a 94 5 speed. Both of my reverse lights dont work when i shift into reverse. i have changed out the switch on the tranny but still no workie. does the switch actually run current through it, if so...theoretically if i run a jumper on the connector the rear lights should turn on. or could it be that the T56 internal parts are not actuating the switch. just looking for some troubleshooting tips. and yes the bulbs are good...lol

thanks!

 

If you check the brown wire at the switch connector, it should be hot with the ignition on. If it is, then jumping the brown and light green wires of the connector should by pass the switch and energizes the back up lights if there is also a ground at the sockets.
You can check the switch for operation by placing the transmission in reverse gear, then use a meter set on ohms to see if you have continuity through the switch contacts. If you have continuity, take the transmission of gear and check again. This time you should not have continuity and this would show the switch is working properly.

 

Alright i have voltage at the connector at the back-up light switch. also checked the operation of the switch itself (beeping from meter indicates continuity) while in reverse, and disconnects/opens when i take it out of gear. my chilton manual wire diagram states the reverse light circuit shares the same fuse as the turn signal so the fuse is good. i might need to check the ground...any ideas where it might be for the reverse lights?...in the trunk maybe? going to pull the light assembly and use the meter to see if i have ground continuity to the chassis. i think they share the same ground. only problem... i locked my car with the keys in the ignition and its on, not running though. yea, i am a dumb a$$. wife is at work and its getting dark, i will finish this up tomorrow!

 

check for power and ground at the bulb socket. usually is a bad socket, the connections at the socket gets worn down and wont make a connection.

 

The backup lights use the same ground source as the tail/stop and side marker lights in the rear. It connects to the body at the rear hatch latch. I would do as Craby said, check for power and ground at the sockets and go from there.
You know, after thinking about this for a minute, if neither backup light is working, the problem is probably something in common to both lights like the power supply. A problem with a ground at both sockets seems unlikely since they are wired individually from a splice that all the other rear lights use. Pull Connector 400 apart (left rear of car as shown in attached drawing) and check the light green wire coming from the switch for power to a body ground. Chances are, you could have a poor connection here or a break in the green wire coming from the switch.

 

Thanks for everyone's help, i found the issue. the issue was self induced. Years ago (after i bought the car new), i installed a trailer hitch and wired it my self. i found a connection on the ground was intermittent. As i was looking and moving the harness around i noticed that the back up lights flickered. The crimp on connector was not making contact. i installed a butt splice and heat shrink'ed it together. problem solved...thanks again!