electrical

  As with many other items on the Advance Design Series trucks, there were also changes in the ignition switches. Both Chevrolet and GMC shared their several switch changes during the seven year series. In the beginning (1947-1948) a unique three position ignition cylinder and housing was introduced. This was a first for GM trucks. It related to a country...

  Both Chevrolet and GMC used the same steering wheel during the 1947-1953 Advance Design years. To keep the two makes just a little different the horn buttons had a separate design. Thus, the driver was always given a close view of the name of the truck he was driving. Chevrolet: Horn cap is chrome and then painted with steering...

Some trivia from Jim Carter Truck Parts: On the Advanced Design Pickups and larger trucks, the battery was under the passenger side of the cab floor. To protect the battery from road debris (gravel, sand and ice) it was important that it be protected from this coming from the right front tire. Designers of the Chevrolet and GMC installed the...

During the 1930s and 1940s many auto and truck manufacturers protected the long ignition wire between the dash switch to the coil beside the engine. The technology of wire insulation wrap during these early years was a woven cotton covering and it was more susceptible to damage from oil and antifreeze in the engine compartment. For protection, the cloth covered...

  One of the more asked questions on the 1941-46 GM trucks is regarding horn contact parts. Most have been damaged over the years and new owners are unsure how they were originally assembled. Below, is a diagram from a 1940's GM Master Parts Catalog and gives an excellent view of the parts used in the assembly. Most items are...

One of the more common reasons for slow engine turnover using an original six volt system is under size battery cables. Most of today's auto parts stores only stock the smaller diameter 12 volt design. Unknowing owners mistakenly replace their original worn cables with shinny new ones that are as much as half the diameter as needed. Two ground cables...

  The 1968-1972 hazard flasher unit is not self canceling as in 1967. The only way to cancel the later hazard flasher is to pull the knob out. This feature was incorporated into the 1968 truck so that the hazard flashers could be operated when the vehicle is being used for slow speed operations. It became a problem in 1967...