CAT 1251303 SWITCH AS for C18 Caterpillar Part - WSTPARTS
WSTPARTS supplies the 1251303 SWITCH AS, a CAT Switch/Relay replacement part designed for Caterpillar C18, C15 and C7 applications. It is categorized under Switch/Relay. Every unit is fitment-verified before dispatch. Manual reference: 3126B: ELECTRICAL AND STARTING SYSTEM, group 205-8657, page 525; 3406E: ELECTRICAL AND STARTING SYSTEM, group 131-8284, page 369.
1251303 SWITCH AS for Caterpillar C18 — Genuine & OEM Replacement Part
WSTPARTS supplies genuine and high-quality OEM replacement SWITCH AS (Part # 1251303). Designed for CAT C18, C15, C7, 3406E equipment.
Compatible Models
Key Features
- ✔ 100% compatible with CAT C18, C15, C7, 3406E
- ✔ Meets Caterpillar original quality and performance standards
- ✔ Genuine CAT parts with anti-counterfeit label | OEM alternatives with warranty
- ✔ Available for order, contact for lead time
Specifications
| Part Number (MPN) | 1251303 |
| Product Name | SWITCH AS |
| Brand | CAT |
| Applicable Models | C18, C15, C7, 3406E |
| Weight | 0.23 kg |
| Condition | New (Genuine / OEM Equivalent) |
| Warranty | 12 Months |
Where This Part Fits
Every row below is a real listing of 1251303 in the Caterpillar parts manual: the machine it is published under, the system it belongs to, the group number and the manual page. Use it to confirm the part against your own parts book before ordering.
| Machine | System | Group No. | Manual Page |
| 3126B | ELECTRICAL AND STARTING SYSTEM | 205-8657 | p.525 |
| 3406E | ELECTRICAL AND STARTING SYSTEM | 131-8284 | p.369 |
| C15 | AIR INLET AND EXHAUST SYSTEM | 185-1676 | p.729 |
| C18 | AIR INLET AND EXHAUST SYSTEM | 185-1676 | p.419 |
| C7 | ELECTRICAL AND STARTING SYSTEM | 205-8657 | p.628 |
| C15 | AIR INLET AND EXHAUST SYSTEM | 283-6414 | p.733 |
| C18 | ELECTRICAL AND STARTING SYSTEM | 205-8657 | p.489 |
| 3406E | SERVICE EQUIPMENT AND SUPPLIES | 147-7847 | p.496 |
System Notes — ELECTRICAL AND STARTING SYSTEM
The electrical and starting system covers the battery, starter motor, alternator, wiring harness, relays, switches and the instrument panel. It carries current from the batteries to the starter to crank the engine, and from the alternator back to keep the batteries charged. Because these machines work in dust, vibration and wide temperature swings, connectors corrode, harness insulation chafes against the frame, and starter solenoids burn out from repeated short cranks. Parts in this group are usually replaced on a symptom basis — slow cranking, a dash warning, lights that dim under load, or a no-start condition traced to an open circuit.
System Notes — AIR INLET AND EXHAUST SYSTEM
The air inlet and exhaust system covers the air cleaner housing and elements, intake piping, turbocharger, aftercooler, exhaust manifold, turbo mounting hardware and gaskets. It delivers clean, dense air and carries hot gas away. On this group, the two dominant failures are dust ingress and heat cycling: a leaking intake joint lets unfiltered air straight into the cylinders and dusts the rings in a few hundred hours, while exhaust manifold and turbo flange gaskets crack from repeated heat cycles and start whistling or sooting. Parts are replaced when boost drops, the intake tract shows dust trails past the filter, or a soot streak appears at a joint.
FAQ
Is 1251303 the right part for my machine?
Match the part number on your old part, or send us your equipment serial number — WSTPARTS verifies fitment free of charge for CAT C18.
Genuine vs OEM replacement — what is the difference?
Genuine CAT parts carry an anti-counterfeit label. OEM equivalents are built to the same specifications, bench-tested and supplied with full warranty at a better price.
Stock, shipping and warranty?
Lead time confirmed on request; we quote the fastest available option. Every order is covered by a 12-month warranty.
📞 Get a Quote: Contact the WSTPARTS parts team | Email: cat@wstparts.com
