If a cycle fails on the test then this will be indicated by a red LED and alternatively a green LED if relay works.
eBay
5-LED EMF Meter Magnetic Field Detector Ghost Hunting Paranormal Equipment Tester Portable Counter Professional EMF Meter Tester
Aliexpress UK
• Suitable for testing DC circuits with a voltage between 3 and 28V. • No earth leads to get tangled - simply contact the wire to be tested and touch your finger on bare metal ground to get reading. • Tester illuminates LED, buzzes and vibrates on contacting live wire. • Model No. AK415
eBay
Type-C USB Tester Digital Display Voltmeter Ammeter DC Voltage Current Meter Power Bank Phone Charger Tester DC 4.5-50V 0-12A
Aliexpress UK
Supplied fitted with two long-life N-sized batteries. � Supplied fitted with two long-life N-sized batteries. We will do everything to solve any problem. Wide Range of P. Headquarters is based in Northampton, England.
eBay
USB Current Voltage Capacity Tester Volt Current Voltage Detect Charger Capacity Tester Meter Mobile Power Detector
Aliexpress UK
Suitable for 6-24V DC circuits. Knurled brass body with test light. Probe tip is covered with protective brass screw cap. Supplied with cable and alligator earth clip. � Supplied with cable and alligator earth clip.
eBay
1S 2S 3S 4S 5S 6S 7S 3.7V-29.4V 18650 Li-ion Lipo Lithium 12V Battery Level Indicator Tester Capacity Tester Meter
Aliexpress UK
Identifies polarity of circuit being tested on LCD display, red for positive and green for negative. Supplied with 3m coiled cable and insulated crocodile earth clamp. Do not use on air bags.
eBay
YR1035+ 4-Wire Internal Resistance Tester High Accuracy Lithium Battery Internal Resistance Tester 100V Electric Vehicle Group
Aliexpress UK
6-24V Auto Probe with an integral worklight to aid use in dark engine bays plus an audible circuit tester for when the LED on the probe cannot be seen.
eBay
USB Tester Type-C PD Color Digital Voltmeter Vurrent Meter Ammeter Voltage Power Bank Charger USB Current Tester Measurement
Aliexpress UK
Suitable for spark ignition engines. Quick and simple fault diagnosis.
eBay
Grip Strength Tester Electronic Tester 396Lbs/180Kg Digital Dynamometer Grip Strength Meter USB LCD Screen Hand Grip Dynamometer
Aliexpress UK
Connects to the vehicle’s own battery and reaches all corners of the vehicle with 5m cable. Checks for short circuits and bad earths quickly and easily. Power-up components prior to installation and check in situ function of components and accessories allowing fast problem diagnosis.
eBay
Portable Non-Contact Alcohol Tester with LED Digital Display Alcoholmeter Alcohol Tester Accuracy Breathalyzer Diagnostic Tool
Aliexpress UK