Alternators

A battery that keeps going flat, or lights that dim at idle, can point to a tired alternator. In this category we gather alternators for Jeep, e.g. CJ and Wrangler models, in several output ratings, so you can match your vehicle's electrical demand.

What does the alternator do?

The alternator converts the engine's rotation into electricity that charges the battery and powers the electrical system while driving. The voltage is controlled by a voltage regulator, which, depending on the vehicle, sits in the alternator or separately. Low charging can therefore also be caused by the regulator, the belt or the wiring, so measure the voltage before you replace anything. You'll find cables and connectors under charging system accessories, and other parts under charging systems.

How to choose an alternator

Start with model, year and engine: the alternators from OMIX are listed for e.g. Jeep CJ, Wrangler YJ and Wrangler TJ, and some variants are intended for the 4.0L engine. Then choose the output based on your consumption – in this category it ranges from 63 to 160 amps. If your project has extra lights, a winch or a fridge, a higher amp rating can give more headroom. However, check that the bracket, pulley and connectors fit your specific vehicle, and that the cables can handle the current.

Frequently asked questions

How do I know if the alternator is faulty?

Typical signs are an illuminated charge warning light, weak starting or lights that dim at low revs. Measure the voltage across the battery with the engine running; it is typically around 13.5-14.5 volts when charging is working.

Can I switch to an alternator with a higher amp rating?

It may be possible if the alternator fits your vehicle's bracket, pulley and connectors. Also check that cables and fuses are sized for the higher current, and compare the part number with your vehicle's year and engine.

What should I watch out for when fitting it?

Disconnect the battery's negative cable first. Check the condition and tension of the belt, and clean the ground connection and cable lugs. A worn belt or poor ground connection can cause low charging, even with a new alternator.