my "RR Diff Lock" light was on....

[brelandt]

after I started my truck leaving work yesterday. Here is the kicker. My truck does NOT have a rear diff locker! It's not there. I do not even have a button anywhere in the truck to control one either. Yet there it was all lit up on the dash board like I was ready to hit the trails.
I stared in disbelief for a minute. Then I looked for a button to turn it off even though I know there isn't one.
So I just placed the transmission in Reverse to leave and 2 seconds afterwards the light goes off. never came back on.
Why is there even a bulb there? Just weird......why would it turn on as well?

 

[The motor guy]

They make gauge clusters that have a light for all the options possible and just put it on your vehicle even if you don't have that option.

 

[NHGUY]

Its probably not a bulb but an LED soldered into the cluster,and the Body Control module should not have function over an option that isnt there.Maybe it was built on a Monday...

 

[Thermo1223]

Bad ground bleeding voltage back? I've seen indicator lights do weird things when they don't have a good path to ground.

 

[Kiwi_ME]

Blame the computers...

 

[bdcardinal]

Yup probably just one cluster for that engine in the truck. I just rebuilt the cluster in my Mustang and there was a bulb in there for O/D Off, even though my car has 3 pedals.

 

[brelandt]

What is strange to me isn't really the fact that there is a bulb there. It's the fact that there is "no" wiring to think of to control the light to turn on let alone to switch off exactly at the time I put the transmission into gear!
If that bulb is truly connected then "what" controls it when the lack of not having the option or it's harness to start off with?
I can't see it being a gauge issue or else other lights would have acted up. Also it wouldn't respond to gear inputs.
Tried researching this but not knowing how to type my problem into google just returned a lot of other things not leading up to what I am looking for.

 

[NilsonCain]

I thought this happened to me when I had a Tacoma... turns out it was the sun somehow making it look that way. I was completely baffled for a while.