No diff lock system but the "RR DIFF LOCK" light is on.

Hi, A puzzle. Today, driving my 2001 Tacoma 2wd at about 45 mph I noticed that the "RR Diff lock" light was on. Didn't know what it was. Looked it up in the manual and online and realized that I have no switch on the dash to turn the differential lock off and on. In fact I looked under the truck and could not find the diff lock unit itself. It's not mounted on the differential, driver's side by the drive shaft. I really don't think I have one and the truck was riding along fine as I said at 45-50 mph.
I just had some work done on the frame and had new rear shocks installed so there was a lot of activity around that rear end. Any suggestions on what the cause might be and how to turn the light off would be greatly appreciated.

 

Is the light real bright?? Maybe just bright enough to notice ?

Another circuit grounding via the locker light circuit.

 

OK. That sounds like a nest of wires somewhere. I have been looking for a hanging wire but found none.
Don't know how bright the light should be but it seems normal brightness. I will turn the key on and compare it to the
other red lights.

 

A pic would be helpful if you can post one.

That sounds weird though, I didn't think that the non TRD models even had that light on the dash.

 

AFAIK, that light doesn’t illuminate unless it’s grounded?
If it’s the same a a 2000 model truck, the wire should be Blue/Yellow.

This is for a 2000 model. Yours may be different.

Pin# 7of C13 connector to the meter.

 

FWIW I believe that all clusters have it but the two I've looked (non TRD) at had no bulb holder behind it

 

TnShooter, Thanks for the schematic. It tells me that there is a wire down there somewhere and I'm just not finding it. Really need to get it on a lift to see what's what.

"I just had some work done on the frame and had new rear shocks installed so there was a lot of activity around that rear end."

 

There may not be a wire, if you don’t have a Diff Lock.
They may not have run a wire to the plug. There really wouldn’t be a need for it.
It can’t hurt to take a look?

 

It seems like there must be. No wire, no light.

 

I have seen a couple of '01 4wds without the locker that were factory wired for it anyway, on the front-end harness down to the connector under the drivers seat. Never heard of it on a 2wd before, but I guess if they had a surplus of TRD wiring harnesses at the factory that day... You can tell if this is the case because the connectors for a difflock ECU and switch would be tucked behind the kickplate and under the far left dash.
Also possible that a previous owner(?) swapped in a replacement inst cluster (with the light) for some reason.

Maybe the easiest thing to do in this case is just take out the bulb and let it ride - or you could check for shorts-to ground while the cluster is out.

 

Even on the 5 lugs? That just seems weird. But I've seen weirder I guess...

 

I think all the clusters have the bulbs my 2000 does with no locker.

Who knows I guess the clusters are all the same .

Doubtful if they are made in house .

I wonder if they have 3 different lines or run so many units then do a change over.

This is one of those problems no locker nothing to get worried about.

I wonder what else might not be working correct if another circuit is grounding via this one ??

 

I had the same thing happen today, when I first started moving it came on and when I stopped about 100 feet later it shut off and didn't come back. I know my 2004 5 lug base RWD has no locker, no wiring for it either, I've used both the empty slots for light switches. Did you figure out where the short was? Gives me an idea where to start looking, previous owner had a remote starter installed that has worked nearly flawlessly for the ten years I've owned the truck, but with any aftermarket modifications you don't do yourself it's a nest I'm afraid to unravel if there's no issue. Just don't want this to be an indication of a bigger short or problem down the road, especially since she's still a baby at only 210,000 miles.
Thanks!