1994 GMC Sierra K3500 pick up truck

Need to adjust timing on newly rebuilt motor, and was told there's a wire called a 'breakoff' wire that goes from the distributor to a terminal block on the firewall or inner kick panel, and must be separated before timing light is used. Cannot find wire. Please help. Jeff

You posted in the wrong forum. Should be somewhere near the distributor, open connector. I believe it needs to be shorted to ground, so that the computer will not make timing adjustments while you are setting base timing. I can't tell you for sure however.

on a 94 that wire is in the area down under the glovebox. it's a tan& blackwire. your timing should be set to 0 with this wire unhooked.