Cummins/Onan — Start-Up Checks
Operation · Control panel gauges
From a Cummins/Onan operator's manual covering: MDL3, MDL4, MDL6. Check it applies to your exact model before use.
Applies to: Cummins/Onan MDL3, Cummins/Onan MDL4, Cummins/Onan MDL6, Cummins/Onan 3A1.7 engine, Cummins/Onan 4A2.3 engine, Cummins/Onan 6A3.4 engine
Procedure
- Observe oil pressure gauge immediately after start.
- Check coolant temperature gauge.
- Check DC voltmeter for charging voltage.
Specs & values
- Oil pressure 30 to 55 psi (207 to 380 kPa) at operating temperature
- Water temperature 165 to 195 F (74 to 91 C)
- Battery voltage 13.5 to 15 V (12-volt Amazon eBay $11.99 FridayParts $65.01 system) or 27 to 30 V (24-volt SinoCMP $247.50 system)
Full service-parts list: Cummins/Onan MDL3 →, Cummins/Onan MDL4 →, Cummins/Onan MDL6 →
Source: Cummins/Onan operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.