I'm having a problem w/88 k-2500. When floor selector is moved into 4H 3-4 seconds later the fuse blows. Checked all connectors no sign of wear/chaffing. Any ideas why fuse is blowing /not engaging 4 wheel drive? Front diff oil level is correct no obvious damage to drive train. Last worked about a month ago, no problem at that time.
Any thoughts/help would be appreciated.TIA.