I recently purchased an 87 D-150,318 automatic.Reverse lights haven`t worked since I bought it.I used a jumper wire to jump across the plug and they came on.I replaced the switch and still no lights. Any help would be appreciated.

 

A bad new switch or not installed properly?

 

It screws into the tranny.Kinda hard to screw that up even for me.I tried the plug both ways,nothing.

 

Some of the aftermarket switches are junk. A guy on another forum did a test on some and found out that most all of the switches bought from places like Autozone were unreliable and had different make and break points of the internal contacts. Use NAPA or Mopar for best results. This is a simple circuit and you have already proven that the wiring should be good. This leaves a defective new switch, and bad ground to the tranny, this can happen just due to old age and isolation from the frame ground due to the rubbermounts, etc. The last thing that will cause it will be the lever inside the tranny, either loose or worn.

For test purposes run a seperate wire from frame ground to the tranny case and see if the lights come on.

As for the switch and lever you need a VOM/DMM meterto test continuity. On the 2 outside pins measure continuity with the tranny in Reverse and the wheels blocked.




Service and Repair

[*]Unscrew switch from transmission case, allowing fluid to drain into container.[*]Move shift lever to Park and then to Neutral positions and inspect to ensure switch operating lever is centered in switch opening in case.[*]Screw switch into transmission case, then add fluid to the proper level.[*]Check to ensure proper switch operation.[/ol]

 

Thanks. I will try the ground thing when I get home tonight.talked to the previous owner and he said the tranny is original so I was having a hard time believing my problem was internal.Do you know how much fluidI can expect to lose?

 

I wouldnt think you would loose more than 2-4 pints. Try jacking up the left side of the truck to minimize the fluid loss

 

Thanks again,