305-0692 (3050692) — Caterpillar (CAT) / Cummins 24V, 200A High-Power Starter Solenoid Relay (Magnetic Switch), designed to control the main power circuit of starter motors in heavy construction machinery, generator sets, and heavy-duty trucks. Image

I. Core Specifications

Part Number: 305-0692 / 3050692

Official Name: Magnetic Switch / Starter Solenoid Relay

Coil Voltage: 24V DC

Contact Capacity: 200A (High-current capacity; specifically designed for starter motors)

Structure: 4 Terminals (2 heavy-gauge main posts + 2 light-gauge control wires)

Type: Normally Open (NO) Magnetic Contactor

Compatible Brands: CAT (Caterpillar), Cummins

II. Main Compatible Models

Caterpillar (CAT)

Excavators: 320D, 323D, 324D, 325D, 330D, 336D, 345D

Loaders: 950H, 962H, 966H, 972G, 980H

Dozers: D5G, D6R, D6T, D7R, D8R

Cummins Engines

KTA19, KTA38, KTA50, QSK60, QSK78, NT855

III. Alternative / Cross-Reference Models (Directly Interchangeable)

586-114112-6A (5861141126A) (Trombetta / White Rodgers)

230-4073 (2304073)

142-8858 (Low-current version; substitution not recommended)

VI. Common Faults and Diagnostics

Fault Symptoms: No response when turning the key; starter solenoid fails to engage; weak starting power; intermittent failure

Diagnostic Methods:

Coil Resistance: Approx. 30–60Ω at 24V

Direct 24V Power Test: Should produce a distinct "click" sound (strong engagement); the two heavy-gauge terminals should show full electrical continuity

Inspection: Check terminals for signs of burning/pitting, oxidation, or looseness