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Starter arcing when cranking

1993 Nissan maxima

The battery went dead so I put a new battery in and a few days later I had the hood open and I had my wife start the car.
I heard a loud cracking sound and saw a large bright blueish flash above and between the starter solenoid and the body of the starter.I had my wife turn the car off and start it again and it did the same thing again.

What the heck is going on?

I’ll guess , I think the starter grounds through the starter mounting bolts so I would loosen & re-tighten those bolts to make sure the starter was getting a good ground . I would also make sure the connection between the solenoid & the starter was clean & tight & also make sure the wire connections on the starter / solenoid are clean & tight . I suppose worn out brushes in the starter could also cause this .

+1 to Sloepoke. Disconnect your battery’s positive terminals; then address the mounting and connections at the starter. First find out if you need a code to get your radio to work after the battery is disconnected.

If the problem persists, you can take things apart and try to diagnose, or take the starter to an auto electric shop for diagnosis, repair, or replacement.

There is a heavy duty copper strap connection between the solenoid and the starter motor that carries the current load for the motor when the solenoid is turned on. I assume the trouble only happens when the solenoid is turned ON. If so you either have a loose connection there or (hopefully not) a short on the connection to the motor. If the starter motor still tries to work then a short issue is unlikely and there is a loose connection to the connection strap.

The physics of why that can happen, when you energize the starter current flow starts from zero and increases over time in the various starter coils. Current can go to 100 amps or more in the motor coils, 20 amps in the solenoid coil. Either way, that’s a lot of current, and big magnetic field develops. If that circuit is then suddenly disconnected from its power source – either b/c you turn the key from start to on, or the armature motor brushes switch from one segment to the next — current flow in the coil suddenly goes to zero. The voltage from one end of a coil to the other is proportional to how fast the current changes in amps per second, multiplied by the inductance of the coil, so all in all a big voltage can develop in that situation. Hence, a spark. It takes close to 1000 volts I think to produce a sizeable spark in air.

I should say that I’ve never seen a spark from a starter motor myself like that. The connections that get disconnected suddenly and which could produce a spark are inside the motor case on every starter motor I’ve come across, so any spark that occurred wouldn’t be visible. That’s why the posters above are suggesting a loose connection is involved somewhere, as a spark could occur outside the case then, at the loose connection.

Sounds like the positive cable on the starter wasn’t properly tightened when the starter was replaced.

Could be the solenoid which is part of the bendix could be worn out. Usually it cracks from the heat over time. Replacing the starter usually fixes it. All the other advice still applies.

My guess is with Nevada’s … probably when the starter motor gets energized initially it and the engine jumps around a bit and that jiggling disconnects the positive cable to the starter briefly, creating a spark.

Its been cold and raining for the last 3 days but I made a quick check of the wires and they are tight.Its suppose to be sunny and 60 degrees tomorrow so Ill go out and give a good checking out,thanks for all the suggestions Ill let you know what I find tomorrow.

I cant see anything wrong with the starter or the wires connected to it, but today I did notice that when the car is running you can remove the key from the ignition, thats something new.
obviously that isnt suppose to happen,so Im wondering if a problem with the switch could cause arcing at the starter?
maybe the switch isn`t creating a good ground so the starter is arcing to a ground?

The ignition switch is tied to the hot side (+) of the battery, not the ground. It connects power to the solenoid coil in the START position to activate the solenoid. The solenoid closes and connects the battery cable going to the solenoid to the starter motor wire along with moving the bendix gear into the ring gear of the engine.

It seems something is wrong inside the solenoid so I suggest you replace the starter to eliminate the problem. The key lock is a separate issue. If you want to fix that you may have to replace the key lock cylinder.

I can take the key out of both my vehicles when the engine is running. I think of it as a convenience, I can open the trunk without turning off the engine … lol … it’s caused by a combo of the key and lock wearing w/use. I doubt that’s related to the original symptom of starter-arcing. I concur with Cougar above, the most likely solution is to replace the starter.