Transmission I.D. number: PK52118426 2552 6129
I'm putting this edit at the top because it contains an important update. I was able to get the back-up lights to come on by unscrewing the neutral safety switch (NSS) about one full turn. I did this after checking for continuity between the its two outside pins. With the ignition switch on and the gearshift if reverse, I had no continuity with the NSS fully inserted, but after backing it out one full turn, continuity was restored. It appears the NSS that I bought sticks into the transmission too far. Because this is a '96 truck with a replacement transmission of an unknown year, I have to wonder if a different NSS is needed. Before swapping out parts at random, can someone help me identify the model year of this transmission? The number found on the transmission is shown above.
I spent several hours today trying to figure out why my son's Ram has no back-up lights. I searched the forums and learned quite a bit, but am still stumped. Here's where I'm at:
It's a '96 Dodge Ram 1500, with 5.2L engine ("Y" code in the VIN). Mileage is around 117,300, and the truck was only driven about 1,000 miles in the last 15 months, before my father-in-law gave it to my son (age 16) to drive. Sitting idle has been hard on this truck -- for instance, as soon as my son started driving it, the water pump started leaking so we replaced it earlier this week. The transmission also leaked quite a bit but I was able to stop that by tightening the pan bolts.
I should note that this is not the original transmission that came with the truck. The original one went out and dad had a used one bolted on. I suspect this replacement may be a contributing factor to our lack of back-up lights.
I started by checking the bulbs by placing 12v across them. They lit up fine. I then checked the sockets and while they were weathered, I cleaned them up and used an ohm meter to check for continuity between the socket and the connections on the back side of the socket. Zero ohms on the meter, so the sockets are OK. For kicks, I then checked for continuity between the left-side and right-side sockets, and that checked out too, for both the hot and ground connections to the bulb sockets.
I could NOT get any continuity from the sockets' black wire (ground) to the chassis ground.
I checked the fuse and it was fine, and I checked for 12v at the fuse socket and voltage was present.
Going under the truck, I pulled the electrical connector on the neutral safety switch and found one of the three prongs was missing. (see photo, and note there are only two prongs). I thought I had found the problem and went to Autozone and got a replacement. Unfortunately, I still had no voltage at the back-up light sockets after replacing the neutral safety switch.
I traced the wires from the back of the vehicle and wiggled each connections everywhere I found the back-up circuitry passing through a connector. (If I recall correctly, the hot wire for the back-up lights is a light purple, with a black stripe).
I even tried disconnecting the battery for 30 minutes after replacing the neutral safety switch, in case the PCM and/or BCM needed to re-learn after the neutral safety switch was replaced. It was a long-shot that didn't pay off.
The only thing I can think to do that I haven't done already is to check for 12 volts across the wires leading to the back-up light sockets, with the key on and the gearshift in reverse, starting under the hood and making my way back. It's possible I have 12v in the back-up lamp circuitry but there's a break in the wiring somewhere before it gets to the taillight fixtures. I also need to understand why I found no continuity between the black wire going to the lamp sockets, and the truck chassis. I should have checked for 12v across the lamp socket's hot line and the chassis.
Can you guys think of anything else to try? This is my first Dodge so don't assume anything -- if you can think of even the most simple thing to suggest, I won't be offended. Thanks in advance....
Here's a picture of the neutral safety switch with the missing 3rd prong:
EDIT: To test the neutral safety circuitry, I turned the key with the gearshift in Drive and the starter appropriately didn't energize.