Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions
The voltage regulator converts high-voltage alternating current (20/100 V) from the stator into low-voltage direct current (13/1 V) to charge the battery without damaging it. Before testing, visually inspect the silicone back: if it has small holes, it needs replacing. For the electrical test, use a multimeter in "diode test" mode. Connect the positive probe to the positive pin of the regulator and the negative probe to the other three pins. The readings (e.g., 485,456,486) should be similar. If one is very different, the regulator is faulty. Repeat the test with the negative probe on the negative pin and the positive probe on the other pins: again, the values should be consistent. An additional check: start the motorcycle and let it run until the regulator becomes hot. When hot, repeat the test. If the values change significantly, the regulator is defective even if it seems to work when cold.

Posted on 14 July 2026 by ScegliAuto

Video tutorial

Related tutorials

How to test an ABS wheel sensor
How to test an ABS wheel sensor
(Various brands) Various In this very interesting video, we can see the method for testing the ABS wheel speed sensor: we need to take the sensor, disconnect the connector th…
How to Test an Inductive Sensor
How to Test an Inductive Sensor
(Various brands) Various This video describes how to perform a functionality test of an inductive sensor using a simple multimeter. Specifically, proceed as follows: locate a…
How to Test a Starter Motor (Before Replacing It)
How to Test a Starter Motor (Before Replacing It)
(Various brands) Various Before replacing a starter motor, check that the problem is not elsewhere. Measure the voltage at the battery (it should be around 12.8 V). Try to st…

    Frequently Asked Questions

    • Vari - What does it mean when the message "insp" appears on a car? Read answer
    • Vari - What problems does the Kymco Downtown 300i have? Read answer

How to adjust the valve clearance on the Moto Guzzi V85TT

Valve adjustment is very important to ensure the proper functioning of the engine; by following the appropriate instructions, it is indeed possible to adjust the valve clearance of the Moto Guzzi V85TT by yourself. First, put the motorcycle on the center stand and start by removing the cylinder head cover, unscrewing all the fixing screws; then use a feeler gauge to measure the valve clearance, adjusting it according to the instructions in the motorcycle's user manual, following the video tutorial until the end!

Watch the video!


by ScegliAuto

More videos