12V Starter Solenoid Switch SSA5077HE for Modern, Mitsubishi

SSA5077HE Solenoid Switch: What It Does

The SSA5077HE solenoid switch sits between the battery and the starter motor and does two jobs at once: it throws the drive pinion into mesh and it closes the main contact that feeds the motor. Both actions come from the same plunger, which is why a worn contact shows up as a click with no crank.

The contacts inside the solenoid are a service item by design. Each engagement arcs slightly, and that arc erodes the disc and the stud faces. Long before the starter motor itself fails, the solenoid is usually the part that ends the circuit.

Specification Summary

• 12V nominal coil and contact rating
• Pull-in and hold-in coil in one sealed housing
• Copper contact disc with plated terminal studs
• Direct replacement for the original mounting pattern

Reference Numbers and Cross References

These references are used for this solenoid switch in catalogues and workshop parts books:

• 36120-42000
• 235077
• SSA5077HE
• SSA5077KR
• SSA5077LC
• SSA5077VA
• SSA5077YJ
• EX3612042001
• 691501
• 66-0301W
• 669404

Application Notes

The switch is used on Modern, Mitsubishi applications. Fitment depends on the starter family rather than the vehicle badge alone, so confirm the number stamped on the original solenoid before ordering.

Where several starter variants were used on the same model year, the solenoid number is the deciding factor. A switch with the right coil voltage but the wrong stud spacing will bolt on and still fail to carry current properly.

How Solenoid Switches Fail

The first failure is usually electrical rather than mechanical: the copper disc erodes until it no longer makes clean contact on both studs.

The second is the winding. A coil that has been cooked by exhaust heat or contaminated by oil will pull in weakly or not at all, and the symptom is a single click from the solenoid with no rotation.

Fault Symptoms

• No crank, but the starter motor spins freely when tested on the bench
• Chattering solenoid during cranking
• Hot start problems after a long run
• Loose or heat-discoloured battery stud on the solenoid
• Control terminal that reads 12 V with the key in START but no action

Testing Before Replacement

A voltage drop test across the main studs is the quickest check. More than about half a volt while cranking points to burned contacts, and the switch should be replaced rather than cleaned.

Check the earth strap and the battery terminals first. A solenoid is often replaced for a fault that lives in a corroded cable, and the new part fails the same way within weeks.

Installation Notes

Isolate the battery, then photograph the wiring before disassembly. The battery stud and the motor stud are not interchangeable, and reversing them will destroy the new switch on the first start.

After fitting, crank the engine once with the coil lead disconnected to confirm the motor circuit, then reconnect and start normally. Check for a hot terminal or a smell of burning after the first few starts.

Quality Control and Supply

Each production batch is tested for coil resistance, pull-in and drop-out voltage, contact resistance across the main studs and high-pot insulation. Hejian Nuojin Auto Parts Co., Ltd. supplies the switches in neutral packaging with a one-year warranty against manufacturing defects.

Frequently Asked Questions

How do I know the coil voltage is right?

The voltage is stamped on the housing or listed with the part number. A 24V switch on a 12V system will not pull in, and a 12V switch on a 24V system will burn out the winding.

Why does the starter click but not turn?

A click means the coil is working and the plunger is moving. If the motor does not turn, the main contacts are burned, the motor cable is loose or the starter motor itself has failed.

Should I replace the solenoid when I rebuild the starter?

It is the usual practice. The contacts have the same service life as the brushes, and a rebuilt starter with a worn solenoid comes back with the same complaint.

Do I need to adjust anything after fitting?

No adjustment is needed when the number matches. Check the terminal nuts after the first few starts and confirm the control wire is seated.