[gmachinz]

The heater leads absorbs heat from the resistor could so it's a good idea to upgrade the size of them anyway AND use j1128 spec wiring too-which Im fairly certain both companies do. On the 73-up trucks there is a single 14ga lead that supplies power to the climate control and thus all blower speeds except HIGH-same thing....over time with all the heat in the wiring the weakest link is the connector behind the climate control and it melts over time. Seems GM never anticipated these trucks reaching over 100K miles in their life or they'd have designed a better wiring system. Most companies just copy GM wiring schematics-they'd be better served to improve on the shortcuts GM took-and some do but not enough imo.