Chrysler Repair: Back-up lights do not work., chrysler voyager, transmission controller

Question
I have a 93 Chrysler Voyager with a 3.3L. The back-up lights do not come on. I have replaced the bulbs and the switch. Next would be the relay, but I'm at a loss as to where it is, or what else could be the problem.

Thank you for your time.
Tim

Answer
Hi Tim,
Fortunately I have the '93 shop manual and was able to find the relay after a bit of a search. It is under the hood, on the firewall (which apparently is also called the dash panel). On the passenger side of that panel you will see a fairly large rectangular box with a large multiwire connector. That is the transmission controller. Just inboard of that box you will see two relays. The one next to the box is the autoshutdown relay and the one that is inboard of that is the back-up lamp relay. If you examine the socket of the relay you will find that it appears to be oblong. The relay contacts which close in order to bring power to the lamps are the two contacts across from oneanother that span the longer dimension, or another way to trace it: the violet/black wire is connected to the white wire by the relay closing. So you should be able to jumper those wires with the ignition switch turned on and the back up lights will go on if the rest of the circuit is o.k. If that happens, then either the relay is bad, or the other two wires at the relay socket from the trans controller are not actuating the relay coil (violet, tan/black on pins 2 and 3 of the trans controller plug nearby; these appear to span the narrower dimension of the socket).
So that should get you started on chasing this one down. Let me know if you need more help.
Roland