2003 TB 4x4 selector doesn't light or function

[JimCshoe]

The 4 wheel drive selector switch suddenly does not light for the selected AWD, 4x4 low or high. It also does not engage anything.. There are no sounds when you move the switch. Don't really know where to start. The MIL has not come on showing any problem with 4 wheel drive. Found no blown fuses.

 

[JimCshoe]

The 4 wheel drive selector switch suddenly does not light for the selected AWD, 4x4 low or high. It also does not engage anything.. There are no sounds when you move the switch. Don't really know where to start. The MIL has not come on showing any problem with 4 wheel drive. Found no blown fuses.

Posting this as it may help someone. After researching a bit (youtube) found a similar problem. Disconnected negative battery terminal 20 to 30 minutes and then reattached. After reattaching pulled fuse 8 (under the hood) and kept it out 10 seconds or so. Replaced fuse and all is well. For how long, don't know.NO $$$

 

[Sparky]

Could very well have been an iffy fuse connection.

 

[Mooseman]

Or a dying TCCM. Mine would fail when it got really cold. 2002's were know to be flakey though but maybe early 2003's were also affected.

 

[C-ya]

This is posted for future reference as I experienced the same symptoms.

Not sure if any work was done under the dash on the driver's side, but when I got my truck back from getting the heater core changed, the mechanic forgot to plug the connectors in to the TCCM. I was able to pull the panel off the end of the dash and reach in and plug them back in. I'm not sure if they could pop out on their own, but stranger things have happened.

It looks like this:

 

[Chickenhawk]

Try the easiest and simplest things first. The inside of the 4wd selector switch has contacts that can become a bit corroded. Try exercising your switch 50 times or so with the engine off. Then leave it for ten minutes and try it again. On 2002s, it is most likely the TCCM; on 2003s or higher, it seems to be always the selector switch.

The switch itself is only $20 to $30, so if it doesn't work and your vehicle is 2003 or greater, it might be worth just replacing the switch. When mine doesn't work right, no lights light up and it stays in the mode it was set to. My service 4wd light also lights up.