1979 Case 580C Ignition Switch

[MikePhua]

Introduction
The 1979 Case 580C backhoe is a classic workhorse built during a time when reliability and straightforward design were paramount. A key component in its operation is the ignition switch, which not only starts the engine but often includes auxiliary functions like accessory power and push-button start. Troubleshooting or replacing this switch can be a challenge due to its age and evolving part availability—but there are reliable paths forward.
Replacement Options and Insights
A Case owner reported difficulty finding the correct ignition switch replacement for the 1979 580C, describing a plug-in type connector and a separate push-button start. Community input revealed versatile solutions: one user bypassed the original entirely and installed an aftermarket marine-style key switch, eliminating the push-button setup.
Others directed the original poster to an online parts catalog—suggesting that the OEM key ignition (with push-start assembly referenced as #8) matches the factory design. While the exact part number wasn’t explicitly confirmed in the discussion, the context suggests a standard Case ignition switch assembly would fit.[]
Aftermarket Options
Multiple aftermarket vendors offer compatible replacements for later Case backhoe models, including the 580C lineage:
Common aftermarket part numbers include:

• 282775-A1, also cross-referenced as D134737, A77312, among others. These are widely compatible with 580D, 580K, 580L, and related models. Features include four blade terminals, positions for ACC–OFF–ON/ACC–START, and a 30-amp rating; two keys usually included. The key code used is A77313, and the design places it firmly in the OEM-equivalent category. ([turn0search17])
  
• Other listings on platforms like eBay feature generic ignition switches marked as suitable for Case/International backhoe loaders. These cross-overs support models from 580D through 580L Series 2. ([turn0search6], [turn0search10])
  

These parts are typically priced in the $20–$30 range, making them accessible solutions when the original switch is obsolete.
Troubleshooting Related Starting Issues
In cases where the ignition switch seems functionally sound but starting remains unreliable, several common issues emerge:

• Poor electrical connections from the switch to the starter solenoid can prevent full battery voltage from reaching the starter. This can stem from corroded contacts, light-gauge or deteriorated cables, or even poor grounding. Mechanics often recommend upgrading to heavy-gauge (e.g., #1 or 0/00 gauge) battery cables and cleaning contact points—this has resolved similar starting issues on earlier 580 models. ([turn0search13])
  
• Intermediate relay failure—some setups use a small starter relay activated by the ignition switch before engaging the high-current starter relay. A clicking sound from the smaller relay without starter engagement often points to this relay or its wiring as the failing point. ([turn0search13])
  

Parts & Repair Summary

• Available Parts:
  • OEM-style key ignition switch (four-position, two keys) with cross-references 282775-A1 / D134737 / A77312
    
  • Aftermarket marine-style switch (as adapted by an owner)
    
• Typical Price Range: $20–$30
  
• Compatibility: 580C, and other 580-series backhoes (D, K, L)
  
• Warning Signs: Starter not cranking, accessory power failure, ignition switch clicks but no activity
  
• Diagnostic Actions:
  • Inspect ignition switch connector and starter cable health
    
  • Test for voltage at starter when key is turned
    
  • Listen for relay clicks or absence thereof
    
• Solutions:
  • Replace ignition switch with part 282775-A1 or approved aftermarket equivalent
    
  • Upgrade battery/starter wiring and repair any poor connections or grounds
    

Conclusion
Even though the 1979 Case 580C ignition switch may not have a readily published OEM part number in current catalogs, functionally identical replacements are available through aftermarket suppliers under part numbers like 282775-A1. These are affordable and effective. When starting issues persist even after switch replacement, the culprit often lies in cabling, relays, or grounding. Addressing both the mechanical component (the switch) and the electrical infrastructure is key to getting your classic backhoe firing reliably again.