Power Probe Circuit Testers started out as relatively simple test tools, but have progressed and become more advanced as each new version was released. The Power Probe III has been the technician’s top choice for many years now. The introduction of the Power Probe Hook with its advanced testing functions raised the capabilities of Power Probes to a whole new level, and the recent addition of the Power Probe IV, with its numerous improvements over the PP3, adds yet another new dimension to the Power Probe line up.
The question we get asked a lot is, “What is the difference?” “Power Probe III? The Hook? Power Probe IV?” “Which Power Probe do I need?” With each tool having a different mix of features and functions, it can be confusing deciding between the different choices.
In this video we’ll answer these questions and compare the different tools to help you understand their value and which one is best for you.
There are many similarities –
First, all of the Power Probe circuit testers connect directly to the vehicle’s battery and they all have the unique ability to supply circuit breaker protected battery power or ground directly from the tool, which can then power up components on or off the car and give you a true indication of the components actual operating integrity. They all have power cables at least 20 ft. long to allow accurate testing anywhere on the vehicle. The PP3, PP4, and Hook all have DC voltmeters for measuring circuit voltages and all three have built in LED and audio tone indicators that can alert you if there is more than 0.5 volts of voltage drop between the battery and the probe tip. All three also have bright LED headlamps for illuminating your work area.
The differences –
Power and Ground capabilities. Both the Power Probe III and the Power Probe IV can connect to batteries from 12 to 24 volts. Activating the rocker switch will supply power or ground from whatever voltage battery you are connected to. The Hook can connect to and can supply up to 48 volts. Both the Power Probe III and Power Probe IV have fixed 8 Amp thermal circuit breakers and can supply up to 25 Amps for a few seconds. The PP3 and PPIV have field-replaceable rocker switches that apply power and ground, while the Hook has a solid state power/ground switch with selectable switch modes with Momentary, Latch, or Pulse outputs.
The Hook has an adjustable electronic circuit breaker that can be set to any fuse rating from 2 to 65 Amps that not only trips instantaneously but resets and reapplies power automatically. The Hook can supply up to 99 Amps of in-rush current. Voltage and Amp capacity are the same for the PP3 and PP4 while the Hook has the highest Volt and Amp capacity of the three probes.
Volt Meter Modes –
The Power Probe III has a 3 digit LCD DC voltmeter that can measure up to 70.0 VDC. It has a separate “Min” Mode and a “Max” Mode for capturing voltage spikes or glitches. The PPIII also has a limited function AC meter mode (Zero to Peak) for quick tests on signal or sensor circuits.
The Power Probe IV has a Hi-Res LCD screen that is 4 times larger than the PP3 display and a 4 digit voltmeter that can measure up to 199.9 Volts DC or AC. It has two different AC modes, either RMS or Peak to Peak (P-P). The Power Probe IV also displays Min and Max readings simultaneously on the same screen.
The Hook has a 3 digit voltmeter that can measure up to 99.9 volts DC or AC (only P-P AC). It has a two-line screen that displays both battery and tip voltage in DC mode or displays tip voltage and frequency in AC mode. The Hook has the additional time-saving “Smart Tip” feature that allows the Hook to automatically select the required meter mode depending on what type of circuit you probe into. You can also manually select “Voltmeter Mode” that will simultaneously display Active/Min/Max voltage readings.
Resistance Measurement –
Although the Power Probe III can indicate resistance levels, it cannot measure resistance in Ohms. Both the Power Probe IV and the Hook can measure resistance in Ohms. Selecting “FEED TEST” mode on the PPIV will let you measure resistance directly (from 0.1 to 10K Ohms) or measure total circuit resistance from the source battery on live active circuits. Live circuit resistance reading is a unique feature of the PPIV. In this mode, the PPIV also displays both the battery and tip voltage side-by-side for instant voltage drop readings.
The Hook’s “Smart Tip” will automatically select the ohmmeter function when needed and can measure resistance from 0.001 to 15Meg Ohms. The Hook has a selectable Min/Max mode for the ohmmeter and can also display the active resistance of any component while being powered up by the Hook.
Current Measurement –
The Hook is the only one of the three probes that can measure current in Amps. The actual hook is only for hanging and is not an inductive pickup. The Hook only reads the Amp draw of whatever circuit or component you apply power or ground into.
Frequency Measurement –
The PP3 does not have any Frequency or Pulse functions. The PPIV has FREQ CTR mode that displays signal frequency and both negative and positive pulse widths all on one screen. The Hook automatically displays both voltage and frequency if an AC signal detected. The Hook has also has selectable modes for Duty Cycle %, + Pulse Width, - Pulse Width, and a Pulse Counter.
Advanced Features and Functions –
PPIII – When set correctly, the Power Probe III has an Audible Monitoring function allowing you to hear circuit signals through the probe speaker.
PPIV – The Power Probe IV has three built-in advanced tests; FUEL INJ, PPECT, and DRV TST modes.
FUEL INJ mode is a comprehensive test that makes fuel injector circuit diagnosis quick and easy.
PPECT mode works together with the Power Probe ECT2000 Short and Open Finder to help find opens or breaks in wires.
DRV TST mode is usually used together with a scan tool and sets the probe up to be able to test computer module driven outputs.
The Hook – The Hook has many advanced features that are not available in either the PP3 or PP4. The Hook does have a Fuel Injector mode similar to the PPIV. The Hook also has the popular “Hot Shot” function that can load test power or ground feeds. It also includes a “Voltage Reference” mode for selecting your own output voltage from 0.5 to 5.0 volts, and by using the included adapter lead set the Hook can also test relays.
So it really depends which functions will be useful for you and type of work you do. The Power Probe III is a simple yet effective circuit tester suitable for every technician from student to master. The Power Probe Hook’s high power capabilities, “Smart” multimeter, and advanced testing functions make the Hook the most powerful and capable of the three probes. The Power Probe IV is right in the middle as far as features, capabilities, and price but has a few improvements over either the PPIII or the Hook.