A friend has a 99 GMC pickup with aa 5.7 Vortec engine that has an electrical issue. He was driving it and the engine quit. I traced it down to no power to three fuses in the under hood fuse box. There is a pink 14 gauge wire in the fuse box that should be powering up when the key is turned on but does not. I need a wiring diagram that shows where the power comes from the ignition switch to the fuse box and which firewall connector it comes through. Does anyone here have access to the wiring diagrams for this truck? Thanks!! Terry
Thanks heymccall I am saving that diagram. At the top of that diagram ECM-1 fuse 20A I need a diagram that shows the wiring from there to the key switch as well. .
I don't have the diagrams, but if you get to pulling your hair out, here's one for you: The underhood fuse box has all the wiring coming in the bottom. They all go into 4 different bulkhead type plugs, attached to the bottom of the fuse box. IIRC, the middle one has all the wires that power up the ECU and such. If you pull it, it's basically a bunch of female spades. If you've had one with a bad connection, they'll usually char a little, and the sharp angles in the plastic of the connector will deform a little. I fought a crank/no start for a couple days before I found that.