“Carter?”
Charlotte noticed.
Evan did too.
Marcus recovered quickly.
“Problem?”
Charlotte pointed toward Aster.
“Explain.”
Marcus looked at the monitor.
“We reproduce the shutdown at seventy-eight percent sustained output.”
“Battery temperature spikes twelve degrees according to the control unit.”
“Physical probes?”
“Stable.”
“Motor temperature?”
“Normal.”
“Inverter?”
“Normal.”
“Coolant pressure?”
“Within range.”
Evan spoke.
“So the battery isn’t overheating.”
Marcus looked at him.
“That’s what I just said.”
“No.”
“You said the control unit thinks it is.”
Marcus’s expression tightened.
Evan walked closer to the glass.
“The shutdown is triggered by measured battery temperature?”
“Yes.”
“Single sensor?”
“Distributed network.”
“Redundant.”
“Then either multiple sensors are wrong at once, the data bus is corrupted, or something upstream is changing resistance under load.”
Marcus folded his arms.
“Six engineers have been on this since four this morning.”
Evan looked at the car.
“Six engineers can miss the same thing.”
A younger technician looked down to hide a smile.
Marcus saw it.
“Do you work here?”
“Not yet.”
“Then maybe don’t diagnose a prototype from twenty feet away.”
Charlotte said:
“He applied for technician.”
Marcus stared at her.
“And?”
“And I want him to look.”
“No.”
Charlotte raised one eyebrow.
Marcus exhaled.
“Charlotte, this is an unreleased high-voltage platform.”
“He is not touching the battery pack.”
“He isn’t cleared.”
“Then you stand beside him.”
Marcus looked at Evan.
Evan shrugged.
“I can leave.”
Something about that irritated Marcus more.
He pointed toward a workbench.
“Safety glasses.”
“Insulated gloves if you cross the marked zone.”
“You do not disconnect orange cabling.”
“You do not access the pack.”
“You do not alter software.”
“You ask before touching anything not obviously low voltage.”
Evan nodded.
“Fair.”
Marcus gestured.
“Go.”
For the next forty-three minutes, Evan barely spoke.
He did not open the battery.
He did not try to impress anyone.
He started where the failure started.
Sensor network.
Harness.
Low-voltage power.
Ground paths.
Signal integrity.
He checked connectors by hand before using the multimeter Marcus eventually gave him.
He listened to the coolant pump during cycling.
Ran his fingers carefully along a harness routed behind the inverter enclosure.
Stopped.
Returned.
Checked it again.
Marcus watched.
“What?”
Evan did not answer immediately.
He pointed.
“Who installed that connector?”
Marcus leaned closer.
“Factory prototype harness.”
“Supplier?”
“Internal prototype shop.”
Evan removed his flashlight.
“Look at the locking collar.”
Marcus crouched.
“What about it?”
“Material isn’t right.”
“That housing is high-temperature composite.”
“The housing is.”
Evan pointed with the flashlight.
“The internal contact retainer isn’t.”
Marcus stared.