Is there a post about checking out these wires that has pictures? I really don't want to get ripped off at the dealer when I take it in for the service4wd light.

 

lines* not wires... sorry

 

Your service 4wd light could be caused by the front axle being engaged all the time. I would fix that, change the transfer case fluid, and reset the TCCM (disconnect it for 10-15 minutes) then see if the light comes back on.

As far as diagnosis goes, you really would need the codes read off the TCCM and then we could go from there.

 

The service light was already lit when I first got it and hadn't touched the buttons yet, it was still in 2hi. As far as fixing that, am I best to take it to a dealer or any garage?

Where is the control module and how do I disconnect it?

Thanks, I'll do all those things.

Sorry for jackin the thread, I'll shutup now.

 

I just found that my cable was bad and front axles are engaged and probably have been for some time and I have never had a 4wd service light come on? I definitely see the sensor and was curious what it did do, because it never told me there was a problem. Is there anything I can do to make sure the axles will release manually before I put the cable back on? I hope the cable assembly is straight forward. My old cable was broke about 6” from the front end and twisted of removing it from the sensor housing, so I am assuming the end of the cable just slides in beyond the wire clip. Thanks.

 

You can try pulling on the rod that the cable clips into in the front diff to disengage the front axle. If you cannot get it to disengage that way, then you will likely have to pull off the passenger side extension housing to access the engagement collar and fork.

Here are a few posts that explain and show how things work:
S-10 4WD question long
Not Just Another INOP 4x4 Problem
99 LS 4x4 needs help

A snippet from the last link above:

 

Sorry, but also curious if there is anything recommended for an additive or anything special that I may want or need to add to the front diff oil? Since the front axles have been engaged for possibly a long time.

 

Nope, just what I stated above. Being engaged for a long time really doesn't produce a lot more wear than otherwise would occur.

BTW, see my edit above.

 

Thanks for the links and pic, what kind of preasure / vacuum should this take to move in and out? I assume vacuum to be 10-15 lbs, so all should be moveable easily by hand? Thanks.

 

My thought is that the spring inside the cone shaped housing has broken. If that is the case, then it should be an easy fix.

You have to remember that the engine vacuum pulls on the actuator. The size of the actuator (~3 in. diameter = ~7 sq.in.) determines the strength of the pull. If engine vacuum is in the realm of 10psi-vac, then the actuator is capable of pulling 70lbs.