2nd Gen Non-Engine/Transmission Back up lamps staying on . . .

[apkole]

The backup lights on my '99 are staying on. Dealer service advised check wires at the back of the trailer plug. No shorts found. I've pulled the backup lamp fuse - - no help. The only way I've found to get them to go off is to disconnect the batteries. This course of action creates operational issues with the rest of the truck.



Has anyone had this problem? I've checked the connectors on the lefthand side of the truck behind the LF tire. I've traced the wires in the loom back along the frame. All looks well.



My roofing crew was following me back from a job today and said that hitting rough spots in the road (a constant here in Michigan) would cause the backup lights to come on intermittently. I've tried adjusting the wires at every junction, still no help. Checking power control center for issues but nothing found so far.



Time for that new CTD 600 mebbie?



I've got the shop manual, so am attempting to trace it out.



Hints?



Thanks



Andy

 

[Wiredawg]

another possiblity

The factory trailer harness has a lead for backup lights to the trailer. The 7 pin connector has a plug into the back that can get corroded. could be a cross (short) between constant battery and backup lights.



The trailer harness is the only place I can think of where a constant hot and backup circuits appear.



BTW, I cut out the plug and hardwired a Polansky 7 Pin connector. no more corrosion.



Hope this helps, wiredawg

 

[B.G. Smith]

Unplug the elec. connector located on the drivers side of the transmission just to the rear of where the shifter lever goes into transmission. If the lights go out, the problem is in the combination backup light/park neutral switch. Could be just the switch but could also be the rail that operates the switch inside the transmission, it has a plastic liner riveted to it which has been know to come loose. To be able to start/drive the truck if the switch is bad you will need to plug the connector back in but disconnect the wire for the backup lights. bg

 

[apkole]

Thanks for the replies. I'll be checking those possibilities out and let you know what I find.



Wiredawg,



There is a red tab on that connector. Is that a release of somekind that needs to be slid sideways to release the plug? I've been working it but no help.



BG Smith,



Am I to understand that if that rail assy is bad I would be paying for the removal and disassembly of the transmission?

 

[B.G. Smith]

Am I to understand that if that rail assy is bad I would be paying for the removal and disassembly of the transmission? [/B][/QUOTE] If the rail is the problem, only the transmission pan and valve body must be pulled to replace it. bg

 

[rrausch]

My backup lights have the opposite problem. They NEVER work--bulbs are fine.

 

[apkole]

Well, I disconnected the plug by the transmission shift linkage at the trans and no help. Managed to get the plug loose at the trailer plug and inspected wires going into the back. Still no help. Temporary fix for the day (so I wouldn't appear to be a total dufus) was to remove the backup lamps from their sockets.



My (wise) wife commented that maybe I would need to re-wire my plow light harness. A-ha! I haven't checked yet, but I do recall tapping in to the harness to drive a relay which turns on a halogen backup lamp on my accessory bar during the snowplowing season. However, all I remember tapping into was the reverse signal line, not the supply so am not sure what I will find. Stay tuned for further developments on, "As the Reverse Lamps Turn".

 

[Wiredawg]

Ah ha! Wiring Mods.

Ah ha, wiring mods. there is one more point where there is a hot lead and back up light lead in the same bundle.



RRAUSH: Iyou got a standard or auto? If standard, I'll bet your switch in the right side of your transmission is bad. Mine went bad. About $75 at you friendly 5-Star.



Before you buy another one, try spraying brake cleaner in it. The contact either gets corroded or burnt.



wiredawg