Motorcycle electric units have been well-known to strike fear also into some of the many seasoned residence motorcyclemechanics. To make it worse, the wiring is just obtaining even more elaborate with the new bike models. Electrical problemsoften cause an instant phone call to schedule an appointment at the bike shop. But it doesn't need to be thatmethod. Troubleshooting electrical problems is sindicate understanding what each component's attribute is and also thentroubleshooting to get rid of them as the source of the difficulty. Knowing wright here to begin is the biggest hurdle.

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Tright here have been entire books composed on this topic and this guide is not supposed to relocation them. It will certainly,but, help riders understand what each electrical component's attribute is and what problems they deserve to causeif they are malfunctioning. The function of this overview is to aid riders to start the procedure of troubleshootingmotorcycle electric difficulties.

You will need a multimeter and the shop manual for your specific motorcycle to troubleshoot the electricaldevice.

Before you go through the process of technical troubleshooting, you must go ago and get rid of the possible"whoops, forgot around those" concerns. It's happened to also the many knowledgeable mechanics. Checkthe kill switch/button and also the crucial. Your bike might likewise have safety reduced outs that will certainly proccasion you from founding theengine. Some bikes will not begin with the side stand also down, if the bike is in equipment or if the clutch lever is notpulled in. Move on if you are still having actually difficulties while doing the correct beginning sequence.


A good area to begin is at the resource of power. You should make sure that your battery is in functioning condition. (If your bike does not have a battery, youhave the right to move on to the following steps.) First, inspect to make sure that the battery has a full charge. The battery shouldhave 12 volts or better with no fill on it (ignition and lights off). If the battery just steps to a maximumof 10.5 volts after being charged, it is most likely that one of the cells of the battery is shorted.

If the battery has a complete charge through no pack on it, you deserve to then inspect it while you rotate the engine over. Abattery may completely charge, however then drop substantially when under pack. If the battery drops listed below 10.8 volts, itis possible that the battery is no longer operable. Monumental engine trouble deserve to also reason the voltage todrop also far if it is making it tough for the starter to turn the engine over. A great method to tell if this ishappening is to check the battery cables for too much warmth. The charging system of the motorcycle should bringthe voltage of the battery up to around 14.2 to 14.8 volts. Anything over that and also the mechanism is overcharging.Anything under and also the charging system is not able to store up. In both instances, something in the charging systemneeds to be resolved.


It's possible for your motorcycle to begin and also run via a bad battery, yet that have the right to develop even moreproblems choose leading to the bike to run poorly and also miss out on. It's also essential to make certain that the battery thatyou use produces enough amps to appropriately power every one of the electric components.

Main Fuse

A blvery own or faulty main fuse deserve to be a source of frustration for many type of riders asit will kill whatever electric. A motorcycle via a faulty main fusage might create an intermittent connectionthat can make the bike run poorly or totally die at what seems to be random times. This can be frustrating ifnot diagnosed right amethod as it will certainly make it seem choose tright here is somepoint else wrong with your bike. A major fusecan come to be faulty because of age or excessive vibration. It's an excellent principle to keep a spare major fuse on hand also atall times because they can go at any time. If the fusage continues to blow, you will have to inspect othercomponents of your electrical mechanism to watch what is bring about the too much amperage.


Ground Wires

Faulty wire grounds are a really widespread trouble, however can periodically be tough to track dvery own. Symptoms of a badground can array from a fully dead bike to electrical components functioning intermittently. Checking every one of thegrounds on your motorcycle have the right to be done quickly if you know where they all are. If you don't, your servicehand-operated have to have all of the areas detailed.

Fixing faulty grounds is inexpensive and also simply needs a little of patience. It's a great principle to inspect forfaulty grounds beforehand in the troubleshooting procedure.


If you are having actually difficulties via charging, you must first inspect your stator since its task is to carry out theadded power needed to charge the battery during procedure. If the stator doesn't provide sufficient power, thebattery will certainly begin to drain. For troubleshooting, the stator connector that runs to the engine m ust beunplugged. With the connector unplugged, you deserve to test the stator for both resistance and voltage.

To start, you need to initially check for continuity from the terminal tabs of the connector and also then watch ifanypoint goes to the ground. Set your multimeter to Ohms to inspect this. First, use the multimeter leads to checkthe resistance of the tabs by checking A to B, B to C and also then A to C. The multimeter have to read under 1 Ohmfor all 3 (make certain to take right into account the resistance between the leads). Readings over 1.5 Ohms are anindication that the stator is faulty.


Next, check to make certain nothing is going to ground by connecting the red lead to the connector and the blackbring about the negative terminal of the battery. This have to be an open up circuit and also the meter need to not read anything.If it does, the stator is faulty.

Now, switch your multimeter to check out AC voltage. To inspect for voltage, the motorcycle need to be running and shouldbe at around 2000 rpm. Then, measure the voltage from tab to tab, just like before. The actual variety of the voltageis not terribly vital. What you are in search of is that all 3 of the numbers are equivalent. If the voltagenumbers are even more than a few acomponent, the stator is faulty.


The regulator/rectifier on your motorcycle performs two functions. The rectifier percent converts the ACpower from the alternator right into DC power so that it have the right to charge the battery. The regulator ensures that thevoltage is yielded within specific borders, as not to damage the battery. Excess power is converted right into heat bythe regulator to eliminate it. The regulator and rectifier are frequently together in one unit, however for some bikes(mostly older), they have the right to be separate.

To test the rectifier, you will need to disconnect all of the wires and also revolve your multimeter to the diodeattribute. First, examine the positive diode. To execute this, place the positive lead right into the positive diode. Thenattach the negative lead to each of the stator inputs. The meter should not check out anypoint on any of these. Ifthat checks out, connect the negative bring about the positive diode and also attach the positive cause each of thestator inputs. The meter must currently be analysis somepoint. The numbers are not essential.


Repeat the process for the negative diode. This time you need to obtain a reading through the positive lead linked tothe negative diode while connecting the negative bring about the stator inputs. With the negative lead associated to thenegative diode, the meter have to not check out anything while connecting the positive bring about the stator inputs.

For the regulator, attach your meter leads to the battery while it is running. It have to not review better than14.5 volts and also no lower than 13.5 volts. If it is better, the battery will certainly be over charged and also if it is reduced, thebattery will certainly continue to drainpipe as the bike runs.

If these tests do not examine out, you will certainly require a new regulator/rectifier.

Ignition Coil/Plug Wires & Caps

If you are having actually a no-spark difficulty, a good location to start after ruling out shorts, grounds, switches andspark plugs, is the ignition coil, spark plug caps and wires. The plug wire runs from the ignition coil to theplug cap. You deserve to initially inspect to make certain that the plug wires and also caps are all intact. A breakdown in theinsulation deserve to reason arcing in the plug wire. You will be able to watch the wire spark in low light conditions.Plug caps might be cracked, which deserve to cause corrosion or an open circuit. To test the cap, you will have to removeit. Use your multimeter to inspect for resistance. It have to read in the thousands for Ohms.


If your plug wires and caps examine out, you deserve to now test your ignition coil. First meacertain the resistance betweenthe primary wire that comes from the CDI box and also the ground or ground wire. The resistance have to meacertain approximately .5to 1.5 Ohms. If that checks out, you have the right to then measure the resistance between the additional wire (plug wire), w hichmust measure in the thousands. The plug cap need to be removed for this test bereason it can add resistance. Yourshop manual must have the correct specifications for your specific ignition coil.

Pickup Coil

Pickup coils rarely go bad, however at times they carry out. Fortunately, they are not that challenging to test. To begin, youwill need to unplug the connector. Connect your multimeter leads to the connector and also inspect for resistance bysetting your meter to Ohms. Compare your readings with your shop manual's specifications to watch if they arewithin selection. You have the right to likewise inspect the gap between the coil and the magnet. Make sure that it is gapped to themanual's specs.

Source Coil

To test the source coil, you will need to examine the resistance in between the output wire and the ground. Theanalysis have to measure in between 300 and also 500 Ohms, yet refer to your shop hands-on for your motorcycle'sspecifications.


Unfortunately, trial and error cannot be done on a CDI box via simply a multimeter. The just method for a house mechanicto test for the CDI is to swap it through a CDI that is recognized to work-related. It's therefore that the CDIhave to be the last thing that you check. They deserve to be expensive and also if it was not the trouble, you can be stuckthrough two functioning CDI boxes. Eliminate everything else before you buy a new CDI, unless you are fortunate enoughto have accessibility to an additional functioning box.

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Note- If your motorcycle starts and runs fine, however then dies once it warms up, tright here might be a wiresomewright here in the ignition circuit that is shedding connectivity as it warms. If this is the instance, you might have topurchase or have a shop test your coils through a fill tester. You might additionally have the ability to simulate the warmth by usinga heat gun to warm the coils. You can then test the coils as they are being warmed up.