jay3250

on my 1999 silverado the 4 wheel drive system works flawlessly but just the other day the service 4x4 light came on in the dash any direction as to what this may be are greatly appteciated.. 56,000 miles.

sm3earl

Get a scan tool, and hook it up to the truck, That light could mean anything.

BIG BAD Z

i hate to be tellin you this but you could be lookin at a new front dif. have you ever left ur truck in 4 wheel drive while drivin at a high speed. if so then you could be lookin at replacing ur differential. if your lucky though itll mean what mine meant. mine came on a few months ago and all i needed was a new 4wd button panel. these are a lot cheaper than a differential.

Dondobe

sm3earl,
I have a "99" and my service 4x4 light came on and I found the fuse had corrosion on it. Pull out the fuse ,clean the ends off or put in a different fuse in and see if thatcorrects the problem.This fixed mine andthe light hasn't come back in 50K or more.

Good Luck, Dondobe

sm3earl

See it could be stupid stuff like that. But i do agree with BID BAD Z, about driving in 4WD in high soeeds tho.

Good luck.

gobucks

Do you have push button four wheel drive or on the floor engagement? The push button switch could be bad. Seenthis several times. It could be something as a simple as a blown fuse - check this. I've replaced many front axle acutators and 4 low switches - simple fix and relatively inexpensive. I agree with sm3earl - get it scanned first - this will tell you alot. Tom