Diff lock with a mind of it's own!

[dclose@tcadvertising.com]

Hello,
Just got back from a fun trip through the California Sierra Nevada in the '88
80q turbo. No problems except when I backed out of the driveway after the car
had cooled down, the rear diff had locked on it's own. I figured I had
accidentally hit the button until it happened again an hour later. It happened
again when I started for work this morning. Only the green indicator light comes
on, not the switch light. Unlocks itself at about 10 MPH as usual. Didn't happen
after a hot restart. Any ideas? Thanks!
___
Dave