Cummins/Onan — Relay Checkout (E)
Testing & diagnosis
From a Cummins/Onan service manual covering: DL4, DL6, DL6T. Check it applies to your exact model before use.
Applies to: Cummins/Onan DL4, Cummins/Onan DL6, Cummins/Onan DL6T
Procedure
- Connect 12 volts across relay coil terminals; relay should activate if coil is okay.
- Connect a 12-volt source to one side of relay contacts.
- Connect a voltmeter to other side of relay contact and 12-volt source; 12 volts appear when relay energized indicates contact is okay.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan DL6 →
Source: Cummins/Onan service 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.