This document provides a wiring diagram index for a 12V system for various Mack truck models. It contains 55 pages of schematic sheets labeled with names and descriptions. Any sheet marked with (A) has an additional replacement sheet for the Australian market. The document is a technical regulation for Mack Trucks and contains the release details.. Hello everyone, I need some help in figuring out electrical issues on a 1978 U-model that I purchased. I have the service manual and a (generic) wiring diagram for mid-70's R/U model trucks but I am still having difficulty.
![[DIAGRAM] 1978 Mack Wire Diagram](http://ww2.justanswer.com/uploads/AN/Andy3221/2014-10-22_215424_a1.png "[DIAGRAM] 1978 Mack Wire Diagram")
![[DIAGRAM] 1978 Mack Wire Diagram](https://ww2.justanswer.com/uploads/WT/wtolkson/2013-04-12_193448_generator.jpg "[DIAGRAM] 1978 Mack Wire Diagram")
![[DIAGRAM] 1978 Mack Wire Diagram](http://ww2.justanswer.com/uploads/AN/Andy3221/2014-02-03_043607_mack_1.png "[DIAGRAM] 1978 Mack Wire Diagram")
Offenders will be held liable for payment of damages. All Volume WIRE DIAGRAM-CONVENTIONAL, 12V MACK, 2013BP PRODUCT SCHEMATICS 21628497 09 1 (2) 1 (91) WIRING DIAGRAM INDEX. Always check the latest information at the "Wiring Diagrams" location. Utilization of Body Builder connectors ordered and provided by Mack is strongly recommended as your power, lighting, and ground source for body installation, PTO installation, and operation. Cutting into wiring harnesses is not recommended as it may affect CAN Bus messaging.