So when I initially looked at the truck I just bought I took it for a test drive and noticed that the 4WD indicator didn't work, and when I would shift into 4WD nothing was displayed on the cluster to indicate I was in 4WD
I did the cluster actuator self test (hold odo button and turn ignition to on) and every light came on EXCEPT the "SERV 4WD" lights.....so I brought this up.

Something was fixed, and now when I put it into 4WD the indicator comes on to let me know it's in 4WD.... but when I do the cluster test again the who "SERV 4WD" doesn't come on at all...

Anyone got any ideas as to why that would be? 4WD seems to work fine as far as I can tell..... she still isn't insured so I can't go hit up a local field and test it out fully.

 

Is it as simple as that bulb being burnt out?

 

Unfotunately no, because it's on the VFD screen, not a bulb.
They also use LEDs, so not likely to burn out, if it were an LED it would have been tampered with. but this is on the screen and not ... tamperable? I'm going to pull it out and take a closer look at it soon, it MIGHT be some broken solder connections on the back....but it doesn't make sense how the 4WD indicator works now and not the SERV part of it. maybe they fixed a switch? but I can't see them getting into the cluster to do something.
oh god I hope not. I'm terrified of the work other people do on my vehicles.

 

So I've taken this cluster apart down to it's board and I can't see anything that would be causing this problem.

What's confusing me is that the 4WD indicator works fine now for some reason when 4WD is engaged, but does not come on during the cluster test or when it's powered up outside of the truck like the 04 clusters do....so it should be coming on as it's getting no info from the 4WD system.....so I'm really very curious/worried about this, and now wondering what ****ery the mechanics might have pulled to make it work.

Nothing seems off about the cluster so I don't think it's ever been opened or tampered with.

 

I'm going to pop my 04 cluster in the 05 and see what happens when I test the same things, though I am expecting it to work.
It does not make any sense that those indicators don't come on during the cluster test

 

yup the SERV 4WD indicator lights up if I put the 04 cluster in the 05.

This is going to be the one singular problem that will bother me for life if I can't fix it.
it's very clearly down to something with the cluster itself.

The only other thing I could try, but am unable to try, is to connect all 40 pins from the 04 to the 05 VFD screen, and power up the 04.... that way it would send the same signals to just the screen on the 05 and would tell me if somehow the screen is bad.
I'm tempted to just try removing the screen from a parts cluster I have and replacing it on the 05.

 

I'M A DUMBASS!!!!!! MY TRUCK IS MANUAL SHIFT!
Doesn't really explain why the 4WD indicator doesn't come on during a self test....but yeah, I don't think there actually is anything wrong.
I can test on my dads 04 when I see him, he has manual shift too.


A service 4WD indicator is standard equipment on all
instrument clusters. However, on vehicles not
equipped with the optional four-wheel drive system
and electronically shifted transfer case, this indicator is
electronically disabled.