Have PB3 offroad package, read diff lock light comes but won't sta

[grox]

Just bought a 2005 CTT with the PB3 Advanced Technology Offroad Package. It's got 139,000 miles but based on it's condition I doubt it's ever seen a day of dirt roads.

I was testing the offroad setting and when I push the lever forward the 3rd time the red light for the rear diff lock comes on for a couple of seconds then flicks off. After that, if I push the lever forward again it doesn't come on at all, not even if I turn the car off and restart. When I come back the next day I can get the light to come on again but once again it turns off after a couple of seconds.

The hydraulic disconnects for the sway bars work perfectly though:-)

Anyway, as a wild guess I'm thinking the rear diff has never been used and the solenoid or whatever device is supposed to engage it may be "sticking" or hitting too much resistance from lack of use and then disengaging without completing its task.

Anyone had this problem? Any suggestions for inexpensive ways I might be able to get it working?

[wvicary]

Vehicle in neutral and stopped when you try and engage the rear unit?

[grox]

Yup, I put it in neutral, push the lever forward once to light up the low range, again to light up the centre diff lock, third time will occassionally trigger the bottom LED indicating the rear diff lock is being triggered but then the light flicks off. Other times the light won't engage at all.

I've posted this issue on a few other forums and a fellow on another forum posted that he had a Touareg and he said he had a similar problem. He ended up having to replace the motor that engages the rear diff lock. Hopefully mine is just sticking or a fuse is blown. I'll dig deeper...