Fault finding
Generator Fault Finding & Diagnostics
Fault finding is the work of naming the cause before parts are changed. A generator that will not start, drops voltage, or shuts down can fail in several different systems. ProService Generator Repairs tests the symptom on site across Gauteng and explains what the tests show.
- Test before parts
- Starting, fuel and electrical
- Onsite across Gauteng
Diagnosis first
What does generator fault finding involve?
It starts with what the generator actually does. A click, a crank with no fire, a start that then dies, a run with no power, and a run that trips when the building connects are different faults. Each one points at a different set of checks.
The usual areas are the start system and battery, fuel delivery, the controller and its alarms, the ATS and start signal, cooling and oil-pressure shutdowns, engine speed and frequency, and the alternator, AVR and output wiring. A part is replaced when the test supports it, not because it is a common spare.
After the fault is identified, the set is run again against the original symptom. A start test is not the same as a load test. If the question is whether it can carry the building, that is a separate check.
Where the checks go
Starting, electrical, fuel and control diagnosis
Generator starting fault diagnosis
No crank, a click, or a failed automatic start. The battery path and the start request are separated before the engine is condemned.
Generator electrical fault diagnosis
The engine runs and the building does not. Voltage, the breaker, the AVR and the alternator are metered rather than guessed.
Fuel-system diagnosis
A crank with no fire, or a run that dies, can be air, a blocked filter, or fuel that has aged. Filters are cleared before pumps are replaced.
Controller and alarm diagnosis
The display is read. A shutdown, a wrong mode, or a sensor alarm is not cleared by disconnecting the protection.
Alternator and AVR diagnosis
No voltage, low voltage and voltage that moves are not the same result. The regulator is proved before a rewind is recommended.
Cooling-system fault finding
A temperature shutdown is checked against coolant, airflow and load. It is not treated as a fuel fault because the engine started.
After the cause is known
Generator testing after diagnosis
Send the symptom in plain language, plus photos if you have them. That is enough to book the visit.
What information should I send before a callout?
Suburb, fuel type, whether it cranks, whether it has ever made power, any alarm text, and a photo of the data plate and the controller screen.
A repeat of the symptom
The set is run the way it failed: no start, a short run, or a run onto load, depending on the complaint.
Output after a repair
Voltage and frequency are checked once the engine is stable. A yard start does not prove the building load.
The next page if the fault is known
No start, no power, low voltage, unstable voltage, low frequency, overheating and a failed automatic start each have their own page.
Related Pages
Fault pages and the systems we test
- Generator Not StartingNo crank, click, or no start
- Cranks But Won't StartTurns over, will not fire
- Not Auto StartingFails only on mains failure
- Starts Then StopsFires, then shuts down
- Not Producing PowerRuns, no usable output
- Low VoltageOutput is present but low
- Unstable VoltageVoltage moves or lights flicker
- Low FrequencyHz or engine speed is low
- Trips Under LoadFine until the building connects
- OverheatingTemperature shutdowns
- ATS RepairsTransfer and start signal
- Controller RepairsAlarms and the control module
- Alternator RepairsOutput end of the set
- AVR RepairsRegulator when voltage is the fault
- Fuel System RepairsFilters, air and delivery
- Battery Not ChargingFlat after the set has been standing
- Starter Motor RepairsClick or no crank
- Fuel Solenoid RepairsNo fuel release on a diesel
- Black SmokeSoot from incomplete combustion
- White SmokeUnburnt fuel, not automatically coolant
- Low Oil PressureReal pressure versus a false alarm
- Generator CalloutsHow the visit is booked
Google reviews of ProService Generator Repairs
Google Review
[ProService Generator Repairs] is a complete end-to-end provider. From complex fresh installations to emergency fault finding and automated refueling, they handle our entire power infrastructure flawlessly and professionally.
Google Review
Fast fault-finding when it won't start.
Common Questions
Questions about generator fault finding
What is generator fault finding?
It is onsite testing that identifies which system failed before parts are replaced.
Do you replace parts before testing?
No. The symptom is tested first. A part is changed when the reading supports that replacement.
Can one symptom have more than one cause?
Yes. Possible causes include the battery, fuel, a controller alarm, cooling, speed, or the alternator. The visit separates them.
What should I tell you when I book?
What the generator does, the fuel, the suburb, and any words on the controller. A plate photo helps.
Is a generator that will not start the same as one that will not start automatically?
No. A set that starts on manual and fails only when the mains drops is an automatic-start fault, not a general no-start.
Is no power the same as low voltage?
No. No usable output and a voltage that is present but low are different tests.
Do you diagnose controllers and transfer switches?
Yes, when the alarm or the failed transfer is the complaint. Live switchgear is not a customer adjustment.
Do you cover Gauteng?
Yes. Technicians travel to the generator across the main Gauteng regions.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Service Areas
Onsite visits across Gauteng
Technicians travel to the generator. These are the main Gauteng areas. Suburb pages sit under each region.
What to send before we attend
ProService Generator Repairs confirms an onsite visit from these details. Send what you have. A missing model number does not stop the booking.
- Location
- The suburb or site, so the visit can be booked in the right area.
- Make and model
- The generator brand and model, if they are known.
- kVA
- The size printed on the data plate.
- Fuel type
- Diesel, petrol, LPG, natural gas, or dual-fuel.
- Controller model
- The module name on the panel, when it is visible.
- Fault or alarm
- What the set does, and any text on the screen.
- Photos
- The generator, the data plate, and the controller or alarm. Send these on WhatsApp.
Book a Visit
Describe the symptom
Call or WhatsApp 082 057 4605. Say what the generator does, not only the brand.
- Call
- 082 057 4605
- Message us on WhatsApp