Every trucker knows how much depends on a reliable start. Behind that reliability is a part you don’t see working but always depend on — the alternator. It keeps your battery charged and your systems powered mile after mile. However, when it starts to fail, the signs can be small and easy to miss. That’s why taking a few minutes for a quick yard check can save you from a breakdown later.
Here are a few quick checks you can perform on truck alternators to determine whether they need replacing:
- Visual Inspection. Start by checking for loose electrical connections, cracked housings, or corrosion around the alternator terminals. A worn or slipping drive belt can also affect an alternator’s charging performance, so if it looks glazed or frayed, it might be time to replace it.
- Voltage Testing. If you have a multimeter, check your alternator’s voltage. With the engine off, it should read around 12 volts. Once you start the engine, that number should climb to somewhere between 13.5 and 15 volts. If it doesn’t, or if the reading jumps around, your alternator might not be charging properly.
- Battery Disconnect. This test confirms whether the system depends solely on the battery, but it requires care. With the engine idling, carefully disconnect the negative battery cable. If the engine stalls, the alternator is likely failing to produce enough current to keep the truck running.
- Check Warning Lights. If your battery light stays on after you start a truck, don’t ignore it. It’s one of the easiest signs that your charging system needs attention. Catching it early can prevent unnecessary downtime in your fleet.
Healthy truck alternators will keep your fleet running smoothly and your schedule on track. At Eubanks Auto Electric, we offer a wide selection of quality, heavy-duty truck alternators. We’ll help you find the right fit to keep your trucks on the road.