Standard Ignition TCA-25 4WD Indicator Light Switch

4WD Indicator Light Switch for Transfer Case Systems

Standard Ignition TCA-25 is a direct-fit 4WD indicator light switch for transfer case applications. It is built with high-quality materials for demanding underbody conditions and is tested for reliable operation in service.

Compatible With Chevrolet Blazer, GMC Jimmy, Chevrolet K10, Chevrolet K20, Chevrolet K30, and related Chevrolet and GMC 4x4 trucks and SUVs from 1981-1991. This Standard Ignition TCA-25 replacement supports accurate four-wheel-drive indicator lamp function when the transfer case is engaged.

• Direct-fit OE replacement for transfer case indicator lamp circuits
• Female connector and female terminals for the specified application
• 2 terminal bullet-style connection
• Built to withstand harsh driveline and axle environments
• Paraphrased OE-style replacement for 1981-1991 Chevrolet and GMC 4WD platforms

Detailed Product Overview

This 4WD indicator light switch monitors transfer case position and sends the signal needed to illuminate the four-wheel-drive indicator lamp. It is a practical replacement for worn or intermittent switches on Chevrolet Blazer and GMC Jimmy models, as well as Chevrolet K10, K20, K30, and GMC K1500, K2500, and K3500 applications. Standard Ignition TCA-25 is engineered as a direct-fit replacement to simplify service on compatible transfer case setups.

This part cross-references 1S3866 and SW4140 for the same application. Standard Ignition TCA-25 is also listed for multiple Chevrolet and GMC truck and SUV platforms where the switch is mounted on the transfer case.

Common Problems This Part Can Address

• 4WD indicator lamp does not illuminate when the transfer case is engaged
• Indicator light stays on after shifting out of four-wheel drive
• Intermittent transfer case signal to the dash warning lamp
• Corrosion or wear at the switch terminals
• Electrical connection issues at the transfer case switch

Installation Notes and Fitment

Fits 1987-1991 Chevrolet Blazer, N/A, transfer case switch fitment.

Fits 1989-1991 Chevrolet V1500 Suburban, N/A, transfer case switch fitment.

Fits 1989-1991 Chevrolet V2500 Suburban, N/A, transfer case switch fitment.

Fits 1989-1991 Chevrolet V3500, N/A.

Fits 1988-1991 GMC Jimmy, N/A, transfer case switch fitment.

Fits 1991 GMC V1500 Suburban, N/A, transfer case switch fitment.

Fits 1988 GMC V1500 Suburban, N/A, transfer case switch fitment.

Fits 1988-1991 GMC V2500 Suburban, N/A, transfer case switch fitment.

Fits 1991 GMC V3500, N/A, transfer case switch fitment.

Fits 1987-1989 GMC V3500, N/A, transfer case switch fitment.

Fits 1987-1988 Chevrolet V10 Suburban, N/A, transfer case switch fitment.

Fits 1987-1988 Chevrolet V20 Suburban, N/A, transfer case switch fitment.

Fits 1987-1988 Chevrolet V30, N/A.

Fits 1987 Chevrolet V10, N/A.

Fits 1987 Chevrolet V20, N/A.

Fits 1981-1987 GMC Jimmy, N/A, mounted on transfer case.

Fits 1987 GMC V1500, N/A, transfer case switch fitment.

Fits 1987 GMC V1500 Suburban, N/A, mounted on transfer case.

Fits 1987 GMC V2500, N/A, transfer case switch fitment.

Fits 1987 GMC V2500 Suburban, N/A, mounted on transfer case.

Fits 1981-1986 Chevrolet K10, N/A.

Fits 1985-1986 Chevrolet K10 Suburban, N/A, transfer case switch fitment.

Fits 1981-1983 Chevrolet K10 Suburban, N/A, transfer case switch fitment.

Fits 1981-1986 Chevrolet K20, N/A.

Fits 1985-1986 Chevrolet K20 Suburban, N/A, transfer case switch fitment.

Fits 1981-1983 Chevrolet K20 Suburban, N/A, transfer case switch fitment.

Fits 1981-1986 Chevrolet K30, N/A.

Fits 1985-1986 Chevrolet K5 Blazer, N/A, transfer case switch fitment.

Fits 1981-1983 Chevrolet K5 Blazer, N/A, transfer case switch fitment.

Fits 1981-1986 GMC K1500, N/A, transfer case switch fitment.

Fits 1981-1986 GMC K1500 Suburban, N/A, mounted on transfer case.

Fits 1981-1986 GMC K2500, N/A, transfer case switch fitment.

Fits 1981-1986 GMC K2500 Suburban, N/A, mounted on transfer case.

Fits 1981-1986 GMC K3500, N/A, transfer case switch fitment.

Quality Assurance

Standard Ignition maintains quality control throughout the manufacturing process, and this switch undergoes extensive testing to support reliable operation in automotive service.