I have a 96 Suburban with a 5.7L Vortec - I keep getting TPS low voltage and EGR pintle errors - I have read that they both use a 4.9 V reference voltage (gray wire on each plug). The issue is sporadic and is much worse when it is stone cold which makes me think it is a short - insulation worn or something. But where? I've poked around but it looks like a nightmare to trace the wires. So I'd like to just bypass the wires and run new ones from the power source. I can find the circuits on the schematics but have no idea where the wires/connections are physically in the truck. Any help? Pictures would be great.

Thanks