ELECTRICAL CONTROLS
Identify coil voltage, terminal arrangement, grounding and duty cycle before selecting a solenoid or relay.
Confirm the device function first
A starter-mounted solenoid, remote starter relay, fuel shut-off solenoid and continuous-duty contactor can look similar while performing different jobs. Identify where the component is installed and what circuit it controls before comparing dimensions.
Check coil voltage and terminal layout
Record the system voltage and photograph every terminal. Count both the large power terminals and the small control terminals. Note terminal labels, connector shape, stud diameter and the position of any mounting bracket.
Determine how the coil is grounded
Some devices ground through the metal case or mounting bracket. Others use a separate coil terminal and remain electrically isolated from the case. A wrong assumption about grounding can prevent operation or create an unsafe circuit.
Match the contact arrangement and duty cycle
- Normally open or normally closed: confirm the required switching state.
- Intermittent duty: intended for short operating periods such as many starting or hydraulic-power applications.
- Continuous duty: designed for extended energised periods within its stated rating.
- Current requirement: use supported electrical data rather than appearance.
Compare the 12V three-terminal starter-solenoid reference, the 684-1261-212 intermittent-duty relay (replaces 684-1251-212) and the 48V continuous-duty solenoid. These pages illustrate why terminal count alone cannot establish interchangeability.
Send a complete identification set
Provide the original number, equipment or system type, coil voltage, duty cycle when known, terminal photos, mounting dimensions and required quantity. Browse Solenoids & Relays or request electrical-parts support.
Quick answers
01 FAQAre all four-terminal solenoids interchangeable?+
No. Four-terminal devices can differ in coil voltage, grounding, contact arrangement, current rating, duty cycle, mounting and terminal positions.
02 FAQWhat is the main difference between intermittent and continuous duty?+
Intermittent-duty devices are intended for short energised periods, while continuous-duty devices are designed for extended operation within their specified ratings.
03 FAQHow can I tell whether the case is grounded?+
Use the original wiring information or supported electrical documentation. Do not infer the grounding method from terminal count or housing appearance alone.
FITMENT SUPPORT
Need help identifying a part?
Send us your OEM number, equipment model, engine details or a clear photo of the existing part.