Flashing ABS and RR Diff lock light

Hey guys, I've got a weird situation that's been going on and I wonder if any of you have had experience with this. Ive got an 04 with the factory locker and recently the display light will pop on as well as the ABS light, and then they will shut off for a bit and then come back on. It could be connected to the fact that I haven't had reverse lights for months, and I bought new bulbs so I know it can't be the bulbs.
Yesterday I put the truck in neutral and engaged the locker, put it in low 4, and backed up and drove forward for a bit and the light went away for a bit but then popped back on, but I regained my reverse lights? I really have no idea what I should do besides maybe replace my transmission switch.
Thanks.

 

Do you by any chance have a trailer harness installed? They have been known to cause issues like this. Otherwise, I would start by inspecting the wiring. Both the ABS sensor wires and Locker wires travel up from the rear axle to connectors on the drivers side frame rail just in front of the LSPV. If there aren't obvious issues with the wires, I would disconnect the connections and hit them with some electric contact cleaner. Then keep following those wires forward to where they enter the cab (under the drivers seat), again inspecting them for any damage. There is another set of connectors under the carper un the drivers seat. You'd have to pull the drivers chair and floor scuff molding, but you should be able to peak under there and do the same thing (clean with electric contact cleaner).. Let the connectors thoroughly dry before reconnecting them.

 

I'll try following the wires today and see if I see anything obvious. I do have a trailer harness, I'm not sure if its OEM i'm pretty sure I've got the towing package bc I have the bigger power windows. I've only used the trailer harness once, and the connection was broken before I believe before so that could have messed something up. Is there an easy way to just remove the trailer harness? Or would that not help the issue.

 

You'll have to find where the trailer harness is connected- usually somewhere near the tail lights, maybe behind the drivers side lamp housing, and see how it's wired up.

Not sure how power windows would factor into a tow package. Did you mean power mirrors? Even then, all 2001 + have the same larger style mirrors. 2000 and before had the smaller ones, so I don't think it's an indication of a tow package.. Unless there is an even larger mirror I am unaware of. An OEM tow package would also likely have been a dealer installed add on, and not something from the factory, so it's susceptible to the same pitfalls as an owner / aftermarket installed option.

Anyway, these trucks are very finicky with their ground wires, and trailer harnesses are a known issue in disrupting that. It is odd to see something wrong with both ABS and the Locker lights as they typically aren't associated with those ground issues, but they are all in that same loom, so it's anyones guess.

 

Bad elocker position switch on top of differential.

 

I can’t find a part number on that, is it an aftermarket fix?

 

8422212010

You can unplug the switch to see if it quits blinking intermittently.