Five free practice questions on batteries and starting systems: content area B of the ASE T6 Electrical/Electronic Systems test, 11 of its 50 scored questions (22%). They are in the ASE format: four options, one best answer. Answer each one before opening the explanation. No account, no email.
01The questions
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A battery removed from a truck reads 12.66 volts after resting overnight, which its maker's chart lists as fully charged. Why does the technician still load test it?
- Open-circuit voltage does not show cranking ability
- The rested reading still includes surface charge from driving
- A load test is the only way to find its state of charge
- The load test breaks up sulfation built up on the plates
Show the answer
A. Correct. A battery with shed plate material or high internal resistance can still rest at full-charge voltage. A load test, drawing heavy current, shows whether it can hold voltage while cranking.
Why not the others
B. Surface charge fades as a battery rests, and this one rested overnight, so the 12.66-volt reading is a true rest reading. The load test is needed because voltage at rest shows charge, not current-delivering ability.
C. State of charge is what the rested open-circuit voltage already gave. The load test answers a different question: whether the battery can deliver high current and hold voltage while doing it.
D. A brief load test does not remove sulfation; it only measures performance. It is done because a rested voltage shows charge level, not whether the battery can deliver cranking current.
ID T6-B-006 · Task T6-B-2 (ASE task list)
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A truck's battery hold-down has been loose for months, letting the batteries shift in the box. What damage can this cause inside the batteries?
- Shed plate material and cracked internal straps
- Hard sulfation spreading across the plate surfaces
- Heavy water loss from the cells through the vents
- Corrosion eating through the positive plate grids
Show the answer
A. Correct. Road vibration on a battery free to move shakes active material off the plates and fatigues the internal straps and posts until they crack. That loses capacity or opens a cell, so the hold-down keeps the battery from moving.
Why not the others
B. Hard sulfation forms when a battery is left discharged or undercharged, not from movement. A loose battery suffers vibration damage: shed plate material and cracked internal connections.
C. Water is lost mainly through overcharging and heat, not vibration. A battery free to move is damaged by vibration shaking plate material loose and cracking internal connections.
D. Positive grid corrosion comes with age, heat and overcharging. Movement in the box causes vibration damage: plate material shaken loose and internal connections cracked.
ID T6-B-011 · Task T6-B-4 (ASE task list)
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After a tractor is jump-started with cables from another truck's batteries, which cable connection is removed first?
- The clamp on the started tractor's engine ground
- The clamp on the started tractor's positive terminal
- The clamp on the booster truck's positive terminal
- The clamp on the booster truck's negative terminal
Show the answer
A. Correct. The cables come off in the reverse of the order they went on, so the last connection made, the ground clamp on the started engine away from the batteries, comes off first. Any spark as it breaks happens away from battery gas, and the remaining clamps then come off with no complete circuit.
Why not the others
B. Removing a positive clamp first leaves the cable live while the other end is still grounded, so a slip can short it. The ground clamp on the started engine, the last connection made, comes off first.
C. Pulling the booster's positive first leaves a live cable end hanging from the started truck's positive while the ground is still on. The started engine's ground clamp, the last connection made, comes off first.
D. The booster's negative comes off second. The first to come off is the ground clamp on the started engine, the last connection made, so the circuit is broken away from the batteries.
ID T6-B-017 · Task T6-B-6 (ASE task list)
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A tractor's starter relay is suspected in an intermittent no-crank. Technician A says the relay is checked by energizing its coil and reading the voltage drop across its contacts while they carry the circuit's load. Technician B says a coil resistance within specification proves the relay is good. Who is right?
- A only
- B only
- Both A and B
- Neither A nor B
Show the answer
A. Correct. Technician A is right: burned or pitted contacts show up only as voltage drop while they carry current, so the relay is tested working and loaded. Technician B is wrong, because a good coil says nothing about the contacts.
Why not the others
B. Technician B is wrong: an in-spec coil only shows the winding is sound, while the contacts it closes may be burned. Technician A is right that a loaded voltage drop test checks the contacts.
C. Only Technician A is right. Technician B's coil reading cannot reveal burned contacts, which is the common failure in a relay that switches heavy current.
D. Technician A is right, so this is not the answer: a loaded contact drop test checks the part that wears. Technician B is wrong, because coil resistance does not test the contacts.
ID T6-B-031 · Task T6-B-10 (ASE task list)
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A cranking control wire is being repaired under a truck's frame rail, where road splash reaches it. Which splice suits that location?
- A crimped splice wrapped in electrical tape
- A soldered splice under heat shrink with no adhesive lining
- A crimped splice under adhesive-lined heat shrink
- A tap-in connector clamped over the wire
Show the answer
C. Correct. A sound crimp makes the joint, and adhesive-lined heat shrink seals it and the insulation on both sides so water and salt cannot wick in. Unsealed splices corrode under splash and add resistance to the control circuit.
Why not the others
A. The crimp is sound, but tape does not seal out water and road salt under a frame rail. Adhesive-lined heat shrink over the crimp seals it.
B. Plain heat shrink tightens over the joint but does not bond to the insulation, so splash can still wick in at its ends and corrode the strands. Adhesive-lined heat shrink over a sound crimp seals the joint.
D. A tap-in connector cuts into the strands and leaves the joint open to water, so it corrodes and loosens. A crimped splice under adhesive-lined heat shrink is used instead.
ID T6-B-039 · Task T6-B-13 (ASE task list)
02Answer key
| Question | Answer |
|---|---|
| Q1 | A |
| Q2 | A |
| Q3 | A |
| Q4 | A |
| Q5 | C |
03What area B covers
This content area deals with the battery banks and cranking systems of trucks and tractors: open-circuit voltage on parallel and series banks, load and conductance testing, flooded, AGM and ultracapacitor charging, cables, boxes and hold-downs, jump-starting, low voltage disconnect modules, cranking voltage and starter draw, voltage drop tests, magnetic switches, IMS units, over-crank thermostats, cranking inhibit circuits, ring gears and slow or no-crank diagnosis.
The ASE test specification calls this content area “Battery and Starting System Diagnosis and Repair”. It carries 11 of the 50 scored questions, 22% of the test.
- Read state of charge on parallel and series banks
- Load and conductance test each battery on its own
- Charge flooded, AGM and ultracapacitor storage correctly
- Service cables, terminals, battery boxes and hold-downs
- Jump-start safely and diagnose low voltage disconnect modules
- Measure cranking voltage, starter draw and cable voltage drops
- Test magnetic switches, IMS units, over-crank and inhibit circuits
- Inspect ring gears and sort slow, long or no-crank complaints
04What the questions turn on
Parallel banks hide a weak battery
Batteries joined in parallel share one voltage, so matching readings across a four-battery bank prove nothing about any one of them. When a charged bank sags under normal starter draw, the batteries are separated, rested and load tested one at a time.
What the LVD module sees
A low voltage disconnect module judges voltage at its own terminals. Resistance in its ground makes it see less than the batteries hold, so it sheds loads early. Keeping loads off while charging voltage stays under its reconnect point is normal operation.
High draw, free-turning engine
Starter draw well above specification, with good cable drops and an engine that bars over freely by hand, puts the extra load inside the starter. On a no-load bench test, high draw together with high speed points to shorted field turns weakening the field.
Follow voltage through the control side
With the key in START, readings to the negative post locate an open: voltage present at one end of a switch, thermostat or wire and missing at the other puts the break between them. A solenoid that pulls in and holds clears the control side.
05The other content areas
The T6 test has five content areas. Each has its own page of free questions:
The ASE T6 Electrical/Electronic Systems practice test page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.
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