Agri-Services, Logo
Phone Icon (716) 937-6618

Our frequently asked questions page is intended to give guidance on the most common questions asked when working with tractor's wiring.


Frequently Asked Questions

We hope this information provides the answers you need. If the information below is not sufficient, please reach out to us by phone or email.


How can I identify a cutout relay from a voltage regulator?

A cutout relay on Delco™ and Autolite™ generators is rectangular in shape, and will have a "BAT" and "GEN" terminal located on each end. Cutout relays used on IH tractors are square in shape and will have two terminals on one side and one on the opposite side. The "F" terminal on the IH relay is used only on applications without a light switch. Mechanical cutout relays have a single relay unit. Solid-state cutout relays have (+) and (-) posts, which are connected to match the system polarity.

A regulator have one relay unit and two or three regulating units. Delco and three unit Autolite regulators have three terminals on one side. Some two-unit Delco regulators have "ARM" and a "FLD" terminal on one side and a "BAT" terminal on the opposite side.

How and when do I need to polarize my generator?

All Delco and Autolite generators must be polarized whenever the generator or battery is disconnected. Most of these systems are known as Type-A systems, where the generator field circuit is grounded outside of the generator. To polarize these Type-A generators, momentarily touch a jumper lead from the regulator or cutout relay "BAT" terminal to the regulator or cutout relay "GEN" terminal. This must be done before the tractor is started. Extreme damage to the generator, wiring, ammeter, and regulator (or cutout relay) will result if the battery and generator polarity are not matched.

I want to convert my generator system to an alternator system and I need a wiring harness. What do I need and why can't I use the same harness as the generator?

Some main factors to consider are the amperage output, if the alternator requires an excitation circuit, and if the alternator has an internal regulator. Most wiring harnesses used with generators are intended to be used with and are limited to about 20 amperes. Most alternators have at least a 40-ampere output and the Delco 10SI alternator. If the alternator requires an excitation circuit, it must be isolated from the ignition circuit to prevent back-feeding from harness and needs to include the proper connectors and circuits.

Typical required parts include mounting brackets, adjusting arms, sheaves, belts, ignition resistors, self-energizing conversion plugs, alternators, and wiring harnesses. Most 24-volt to 12-volt conversions also require a starter relay as well as a 12-volt starter.