How to Fix a Car Starter Solenoid

by Chris Stevenson
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Auto Engine image by Andrew Breeden from

The starter solenoid turns an electric signal from the ignition key into a high-voltage signal that activates the starter motor. Serving as a powerful relay switch, the solenoid functions as the initial starting device for the vehicle. The solenoid can transmit as much as 200 amps and it must switch on and off every time the vehicle starts. Sometimes the high-voltage contacts inside the solenoid can burn, carbon-up or stick, resulting in a no-start condition. Replacing the starter solenoid with a new starter does not always have to be done. The solenoid lends itself to repair just like any other component, and savings can be realized by doing so.

Step 1

Place the vehicle in neutral or park with the emergency brake set. Raise the hood and disconnect the negative battery terminal. Raise the vehicle with a floor jack high enough to place two jack stands under the frame near each wheel. Refer to your owner's manual for the proper procedure to remove your starter.

Step 2

Slide under the vehicle and remove the main starter wire and the two (or three) ignition wires on the back of the solenoid. Make certain you know the proper position of the wires for re-installation.

Step 3

Remove the large starter mounting bolts with the proper socket (use a socket extension for hard-to-reach bolts). Pull the starter away from its mount by twisting and turning it until it comes out. Place the starter in a vice, gently clamping the case.

Step 4

Remove the thick wire that connects the solenoid post to the starter. Use a Phillips screwdriver to remove the backing plate on the solenoid (some plates might have small bolts).

Step 5

Pull the small round plunger out, and be careful to note the spring and the small ball on the end of it; keep the spring and ball and remember how it fits on the plunger. Remove the two studs on the outside of the solenoid housing. These studs keep the two copper contacts in place. Remove the old copper contacts.

Step 6

Place the new copper contacts (kit parts) into their seats and insert the studs back into their position. Tighten the two stud bolts. Take the old spring and ball and install (load) it onto the new plunger, provided in the kit. Push the plunger back into the solenoid, holding tension on spring.

Step 7

Place the solenoid plate on, being sure that the spring and ball have aligned with the plate seat. Screw the plate back onto the solenoid, using the screwdriver or small socket.

Step 8

Reattach the thick starter wire to the solenoid and tighten it. Slide back under the vehicle and align the starter to its mounting surface. Replace the mounting bolts and tighten them with the socket and extension.

Step 9

Reconnect the ignition wires and the main starter wire to their posts and tighten them down. Replace any splash shield, cross member or suspension part you removed to gain access to the starter.

Step 10

Lift the vehicle and remove the jack stands. Reconnect the negative battery terminal. Start the vehicle several times, making sure the solenoid makes contact every time.

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