The Hi/Lo and Diff lock indicator lights aren't functioning in my 04. I'm pretty sure this is preventing HDC from operating, since the system isn't aware I'm in Low. Diff lock and Low are definitely working, I just don't get dash lights so I'm suspecting the switches. The PO never used either in 14 years so perhaps they're stuck or something. Anyway, I've got the trans and transfer case out and I've gone through the Electrical Library and the ETM but I'm having trouble identifying which switches do what. My understanding is that there should be four switches on the 04 however the pics in the Elec Lib do not line up with what I find on mine. Is this even close? TIA

1 = Neutral
2 = Hi/Low
3 = Diff Lock
4 = Diff Lock

(List edited to number the switches correctly)

 

Switch 2 is the Hi/Lo. My '04 had the same trouble with HDC and replacing that switch with the green lead fixed mine. You can check continuity at the plug to verify. Hi=Open, Lo=Closed (I think).

Nos 3 and 4 are for the dif lock.

 

Thank you for the reply. That would make sense as the 03 transfer case I have does not have switches 3 and 4. It would also make sense that the trans temp switch would be on the actual trans...

Anyone know what number 1 is for? According to the library it looks like it is a neutral switch. The switch itself is obscured but I think the blue wire goes to it, and it is present on both transfer cases I have.

Edit: Does anyone know where to find the diff lock wiring in either the ETM or the Elec Library?

 

OK, this clears up a lot of my confusion. The other docs I have don't seem to reference the the 04 whereas the Workshop manual does. The diff lock switches are not only different specific to 04 with molded plugs instead of spade-type connectors, there are also two of them for some reason. Hooray. I'm still looking for the electrical schematic to find out how they're wired in but at least now I have confirmation where everything is. Switch number 1 in my pic above isn't shown in this view but it is indeed the neutral switch.