FDY Black Box · User guide
From the box
to your first report.
- 220 V mains
- 4 valve outputs
- 5 V & 12 V valves
- Android app
01 · Connect
Four valves, one plug each
The Black Box runs on 220 V mains. Its four valve outputs share one green connector on the front panel.
- A
- Illuminated button — Starts and stops the stored cleaning program — no phone needed.
- B
- Green connector — Outputs 1, 2, 3 and 4 from left to right, two pins each.
- C
- Screw-terminal plug — Each output has its own plug: use the supplied crocodile cable or wire your own harness.
- 1
Plug in the power
Connect the device to a 220 V socket. - 2
Attach the cable set
Plug the four-way crocodile cable set into the green connector — outputs 1, 2, 3 and 4 from left to right. - 3
Clip on the valves
Clip a red and a black crocodile clip onto the two terminals of each solenoid valve.
Building your own harness?
The green plugs have screw terminals: wire a dedicated harness for your valve group and skip the crocodile clips.02 · FDY app
Pair once, connect in one tap
Install the free FDY app from Google Play, create an account and sign in. Download page
Add device
Turn on Bluetooth and the device, then scan.
- After the first pairing the device stays in your list — open the app and tap Connect.
03 · Simulator
Try the Black Box right here
A virtual workshop bench: use the FDY app on the phone, change things on the bench — unplug a valve, give it a broken coil or a short circuit — and see how the device reacts.
Supply voltage
Press and hold a valve — it runs while you hold and stops when you let go. Live current and resistance appear in its tile.
Workshop bench
Tap a green plug to unplug it, set a valve's condition, or press the device's button to start cleaning without the app. Simulation: sounds are synthesized and cleaning runs 30 times faster.
Try this
Manual
- Press and hold a valve tile on the phone — the valve runs only while you hold it.
- Switch the supply to 5 V and hold the valve again: the current drops, the resistance stays the same.
- Open the device settings (gear icon) and lower the short-circuit limit to 2.0 A — even a healthy valve now trips the lock.
04 · Check connections
See every connection before you start
The Manual screen shows each output as Connected or Not connected.
—
0.00 A
Not connected
5.1 Ω
2.35 A
Connected
—
0.00 A
Connected
—
0.00 A
Connected
- Unplug an output and its tile switches to Not connected — a quick way to check a cable.
- A valve with a broken (open) coil also shows Not connected: if the wiring is fine, that valve is faulty.
- Hold a valve to run it: its tile shows the live current and resistance.
05 · Modes
Five modes, one app
Choose a mode at the bottom of the app's device screen. Each one answers a different question about the valve.
Manual
Press and hold a valve: it is energised for as long as you hold it and stops when you let go. Its live current and internal resistance appear on screen.
- Resistance comes from the supply voltage and the measured current (R = U ÷ I).
- Some transmissions use 5 V valves: choose 5 V under Supply voltage and the outputs switch to 5 V.
- The device stays at 5 V until you switch back to 12 V or restart it.
Proportional PWM
Set a duty cycle between 0 and 100% for each valve and watch the current. A healthy proportional valve moves its piston gradually forward and back as you change the setting.
- For a demonstration, connect a 12 V bulb to an output: its brightness follows the slider.
- Valves heat up when driven for a long time without cooling — don't leave one on longer than you need.
Pulse
Opens and closes the selected valve continuously at the rate you set, until you stop it. You can change the valve and the rate while it runs. Pulse mode is a test, not a cleaning cycle.
- Run identical valves one after another at the same rate — for example 10 pulses per second — and compare the sound.
- A clean, healthy valve gives a sharper, metallic ring; a clogged or dirty valve sounds duller because its pin can't travel the full stroke.
Cleaning
Place the valves in cleaning solution, set the duration and the pulse rate, and tap Start cleaning. Every connected valve is pulsed at full power to help loosen metal particles inside it.
- Each valve pulses at the rate you set — the number of valves connected doesn't change it.
- Empty outputs are skipped. Cleaning stops by itself when the time is up; tap Stop to end it early.
Automatic
Tests every output in turn, measures each valve's resistance and current and builds a report.
- Tap Save PDF, enter the date, the vehicle's chassis number (VIN) and your notes — the report is ready to share with your customer or print.
- There is no fixed good range: the Black Box works with every type of solenoid valve, so compare the readings with the valve's specification or a known-good valve.
Supply voltage
Choose 12 V or 5 V above the modes. The supply can't be changed while a test or cleaning is running, or while the short-circuit lock is active.
06 · Settings & safety
Built-in short-circuit protection
Device settings are opened from the app and stored on the device itself.
Current limits
Cleaning defaults
Short-circuit lock — output 4
Current above the limit was measured on this output, so the device stopped all outputs for safety. Check the valve cable and connection, then reset the lock.
Reset lock- Short-circuit limit: 4.0 A by default. If a valve normally draws more than 4 A, raise the limit step by step — or lower it again.
- Scaled automatically: the limit refers to 12 V and is adjusted for the 5 V supply and for PWM duty.
- Short-circuit lock: if any output goes above the limit during cleaning or a test, the device stops all outputs and warns you. Reset the lock and cleaning carries on.
- Cleaning defaults: the duration and rate used when you start cleaning with the device's button.
- Firmware: device updates are installed through the app.
FAQ
Frequently asked questions
Which valves can I test with the FDY Black Box?+
Solenoid valves that run on 5 V or 12 V — up to four at once, including proportional (PWM) valves. The device works with every type of solenoid valve.
Do I need the app to clean valves?+
No. Connect the valves and press the button on the device once: the cleaning program stored on the device starts and stops by itself. The app is needed for readings, the PWM and pulse tests and PDF reports.
How do I find a clogged valve?+
Run identical valves one after another in Pulse mode at the same rate and listen. A clogged valve sounds duller than a clean one because its pin can't travel the full stroke.
What does Not connected mean?+
The device sees no load on that output: the plug or clip is loose, or the valve's coil is broken (open circuit). If the wiring is fine, the valve is faulty.
What happens if there is a short circuit?+
The device detects it, stops all outputs and shows which output is affected. Check the valve cable and connection, then tap Reset lock in the app — cleaning carries on where it stopped.
My valve draws more than 4 A — what should I do?+
Raise the short-circuit limit step by step in the app's device settings. The setting is stored on the device.
Support
Need a hand? We're on WhatsApp.
Our engineers help you set up the Black Box and run your first test — 24/7.