Heavy Duty Alternator

Why you shouldn't remove the IMS

If you are unfamiliar with the IMS, you may try to remove it—not realizing its many benefits. Many of the Delco Remy brand starters come equipped with an Integrated Magnetic Switch, or IMS. The IMS provides a higher current draw for the motor. It does this by reducing voltage drop and controlling battery current. This ensures the solenoid receives the maximum available voltage in any starting condition. If you are unfamiliar with the IMS, you may try to remove it—not realizing its many benefits. However, doing so would result in significant control circuit problems. It will also void your warranty. If an IMS is part of your gear reduction starter, you should never remove, bypass or uninstall it. This video provides two options for you to consider.

Remote Sense Operation and System Testing

This Tech Tip reviews how the use of Remote Sense can impact diagnosing voltage complaints.

Replacing a Starter with an Offset Pinion

In this Tech Tip Video, we explain why you can replace a starter with an offset pinion with one that is centered. Despite the new starter having a different pinion size, tooth count and placement it may still be able to be used. Starters are designed to match the engine ring gear for proper mesh and performance. Most starters—including Delco Remy branded starters—have a centered pinion. However, some manufacturers use an offset pinion. If the old starter’s pinion is offset and the new one is centered, you will notice the pinion on the new starter is larger in size. The larger pinion is needed in order for the pinion to reach the ring gear when it is centered. Additionally, you’ll likely notice a higher tooth count. An offset pinion, on the other hand, has a smaller pinion size. So, in order for it to reach the ring gear, the pinion is offset and moved closer to the ring gear. Frequently, an offset pinion will have fewer teeth.

Measuring Flange to Flywheel

In this Tech Tip, we’ll review how starter spacers are utilized as well as how to measure the starter flange to flywheel so that during any maintenance, the starter is properly mounted and performs as designed.

Alternator Charging System Troubleshooting

Experiencing problems with your alternator charging system? Squealing noises under the hood. Headlight bulbs that blow out repeatedly or dim. Dash voltmeter gauge out of range—either too high or too low. These are common indicators that something may be wrong with the charging system. If any of these symptoms are evident, then this video is for you. This video will walk you through five steps to pinpoint potential issues.

Fix an Alternator that Won’t Charge by Flashing the Field

Have you ever installed an alternator that won't charge? The Flash the Field Tech Tip video will show you how to easily fix this alternator problem. This strategy only applies to the following Delco Remy alternator model families: 20SI, 21SI, 22SI, 23SI, 26SI, 30SI and 36SI.

Diagnosing Starter Cranking Problems

While cranking problems can be frustrating, identifying and correcting the root cause does not have to be. The first step is to identify the symptoms. In a cranking system, you can divide your symptoms into one of three possible troubleshooting categories: 1. Slow Crank: The starter will crank; however, the engine RPM is slow to start the vehicle. 2. Click No-Crank: The solenoid clicks but the starter doesn’t crank. 3. No-Click No-Crank: The solenoid doesn’t click, and the starter doesn’t crank. In this Tech Tip video, we review the steps you need to follow to identify and then fix your cranking problem.

Voltage Drop Test

The Voltage Drop Test Tech Tip video explains how to conduct a voltage drop test on the battery, alternator and starter. Electrical problems related to excessive voltage drops are more common than you may realize. High or unwanted resistance is one contributing factor that leads to cranking and charging system problems. High resistance is often caused by one of these four main issues: - Loose connections - Corrosion in the cables and wiring - Improperly sized wiring or cables - Improperly crimped connectors A visual inspection of cables and connections doesn’t show what’s going on inside the cables or inside the connections. Voltage drop testing is the only sure method of determining if there’s an adequate delivery path for optimum starting, charging, battery performance, and life.

How to Install an Alternator Pulley

Proper installation of the pulley on a Delco Remy 24SI and 28SI ensures that the product will perform as promised. Unfortunately, damaged products are returned as a result of improper pulley installation. This shows you how to install a pulley in six simple steps.