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ZZ1Y00115a - Northline Parts

Caterpillar 237-3530 Ignition Switch for 303CR 304CR 305CR Excavators

SKU: NLT1Y00115
$33.99 In Stock
$33.99
Sale price  $33.99 Regular price 
Ships for free in 2–4 business days.
This ignition switch replaces Caterpillar 237-3530 on compatible 303CR, 304CR, and 305CR compact excavators with K4N, S4L2, or S3L2 engine applications.
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Compatible Models

We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.

Compatible equipment / model
  • Caterpillar 303CR compact excavator with compatible S3L2 application
  • Caterpillar 304CR compact excavator with compatible S4L2 application
  • Caterpillar 305CR compact excavator with compatible K4N application

Product Overview

A compact excavator that loses dash power, will not energize the starter circuit, or starts only when the key is held in a narrow spot may have worn switch contacts after fuses, interlocks, wiring, and battery voltage are verified.

The switch routes power through OFF, RUN, and START circuits. Compare connector shape, pin arrangement, mounting thread, key positions, and machine serial number; similar-looking switches can send power to different terminals.

Key Features & Performance

  • Replaces Caterpillar 237-3530
  • For compatible 303CR, 304CR, and 305CR excavators
  • Supports K4N, S4L2, and S3L2 applications when specified
  • Restores key-controlled starting and run power
  • New aftermarket switch

Replaces Part Numbers

  • 237-3530

Common Uses

  • Repairing intermittent no-crank operation at the key
  • Replacing a cylinder that binds or spins without reliable electrical contact
  • Restoring dash and run power after circuit diagnosis

Technical Specifications

  • Product Type: Ignition Switch
  • Primary Application: Caterpillar compact excavators using 237-3530
  • Package Quantity: 1 switch
  • Condition: New
  • Replacement Type: Aftermarket
  • Reference: 237-3530
  • Product: Ignition / starter switch
  • Applications: 303CR; 304CR; 305CR
  • Engine References: S3L2; S4L2; K4N
  • Condition: New aftermarket

Installation & Fitment

  • Disconnect the battery ground cable
  • Label the connector and any loose terminals
  • Inspect interlock and starter-circuit wiring for heat damage
  • Test every key position and safety function before operation

Compatibility Notice

Northline Parts does its best to list all known compatible models, but the correct part may fit an application not shown.

Model, production date, serial number, connector, dimensions, installed options, and previous repairs can affect fitment. Compare the original component and reference information before purchase.

Frequently Asked Questions

Q: Can an interlock switch cause the same no-crank symptom? A: Yes. Test seat, lever, and neutral interlocks before replacing the ignition switch.

Q: Does the switch include a key? A: Confirm the listing photos and package contents; the electrical fit still depends on the original switch layout.

Q: How do I confirm this is the correct part? A: Match 237-3530, machine serial number, connector and pins, mounting diameter, switch length, key positions, and engine application.

Q: Is this supplied by the original equipment manufacturer? A: No. This is a new aftermarket item. Brand, model, and part numbers are used only to identify compatible applications.

Part Summary

keywords: Caterpillar 237-3530 switch, 305CR ignition switch, 304CR no crank repair, 303CR key switch, Cat compact excavator starter switch

Brand names, model numbers, and reference part numbers are used for identification and compatibility purposes only. Verify the original component, dimensions, and application before purchase.

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