Will a Motorcycle Start with a Bad Rectifier?

Your motorcycle needs DC power to run, but the charge input is an AC current. The rectifier is what makes the conversion, but can you still start your motorcycle if the rectifier isn’t working properly?

No, if you have a bad rectifier, your motorcycle won’t start because there’s no way to get the battery charged. A rectifier is a component that transfers the AC current to DC, so if there is a problem with the rectifier, the motorcycle won’t be able to use the available power.

A motorcycle requires rectifiers to convert AC into DC power. How should you approach rectifying a motorcycle if you’ve never done it before? What are the possible problems? and can you start a motorcycle with a bad rectifier?

What does the rectifier do on a motorcycle?

A rectifier is an electronic device that converts alternating current (AC) electricity from sources like to direct current (DC). It’s an important part of modern cars, motorcycles, and other vehicles, as well as some home appliances such as hair-dryers, vacuum cleaners, and electric shavers.

Even though they are essential for the proper functioning of most devices in our daily lives, they are also quite dangerous when improperly designed or built.

They can be easily damaged by careless installation, short circuits, overcharging, overheating, improper connections, vibration, temperature changes, or other hazards.

A good rectifier it takes the AC voltage coming from the motorcycle’s generated motion and turns it into a DC voltage. The DC voltage is then sent to the battery charger, which will charge the battery.

Basically, you wouldn’t be able to charge the battery without a good rectifier, and this would lead to a lot of problems with your motorcycle not starting. You would also have to charge the battery yourself because a bad rectifier will turn a good battery into a dead battery or a bad battery.

How to repair a bad rectifier?

If you think you damaged your rectifier as a result of something you did wrong, here’s what we recommend first: check the electrical system of the motorcycle and make sure everything is ok.

If all seems ok, then you know that the problem came from the rectifier, and if it’s still broken then you need to replace your entire electrical system.

It doesn’t matter if you damage any other parts, but to avoid unnecessary trouble just replace your entire electrical system and ask someone else to help you with the rest, especially since you probably want to keep the bike.

But if the problem wasn’t caused by anything external, there’s nothing to worry about. The worst thing about this problem is that it’s really hard to spot it. Although you can see some signs of problems, many problems aren’t immediately visible.

That’s why we suggest taking your bike to an expert who knows his stuff when it comes to repairing them, but if there aren’t any near you, then take your battery to a specialist and ask him to test it and tell you whether or not there’s a problem.

If he says yes, ask him some questions about how to repair it and ask him to give you a quote. In addition, he will identify other problems, such as a bad stator, etc.

How do I know if my motorcycle rectifier is bad?

First things first, you need to check whether the rectifier is properly installed on your bike. Look at your wiring harnesses and make sure you don’t see any loose wires dangling. Once you’re confident everything is in place correctly, you’ll want to take a close look at the rectifier itself.

If something looks suspicious or doesn’t seem right, then you need to replace it immediately since you don’t want anything else to happen. Here we go into detail about how to check whether your rectifier is working properly.

If all seems fine there, then check the main fuse box. This unit helps protect your vehicle against shorts, excessive currents, or voltage spikes caused by faulty electrical components.

Check the voltage level on each cable before and after connecting them to your bike. If the voltage levels aren’t the same, then you might have a problem somewhere. You will also experience a poor start if your rectifier is bad.

The next step is to find out where exactly your charger is located. This could be inside the battery compartment or behind the seating area. Depending on which one it is, you’ll either need to disassemble it to access it or remove it completely.

The last thing we’re going to cover is checking the wire gauge. If it has a thickish color and doesn’t feel too hard, you can probably handle it. Otherwise, you’ll have to use another option. You might not be able to find any replacement parts locally, but luckily you can order them online.


Rectification may seem pretty complicated, but the good news is that you don’t have to be an expert to figure out what’s wrong and fix it. All you need is a basic understanding of electronics and the ability to follow some instructions. Fortunately, it’s easy to learn just enough to repair your own devices.

The above-mentioned solutions are very useful for diagnosing the most common problems. However, if your motorcycle has some more complex issues they cannot be resolved by your DIY skills. In such a case, consider the following options:

Find an experienced mechanic

If you’ve got a reliable professional mechanic whose work you trust, consider asking him to diagnose your motorcycle. He will surely have better equipment than you and will be able to detect minor faults easily. Moreover, he is likely to offer better advice on how to solve these little issues.

Don’t hesitate to get an estimate from a reputable service center

If you don’t have time yourself to search for a qualified garage, you still can choose a nearby workshop and get their advice. They usually have years of experience and are familiar with modern types of motorcycles.

When dealing with professionals, always remember to pay attention to small details – their mistakes are sometimes expensive

Choose a proper shop

Finally, you should visit a trustworthy motorcycle repair shop to get advice. There are several ways to find them:

Go online

Take advantage of social media platforms like Facebook or Google+ and post a call for help. You will receive lots of recommendations, so it won’t be difficult to pick a suitable business.

Look for a company website

You can also visit the relevant firm’s website to see their reputation as well as reviews written by previous customers.

A final word

Having said all this, I would recommend you find a professional to perform repairs instead of doing it yourself. A poorly performed job can result in worse damage. So be careful when choosing a mechanic and keep in mind that spending money isn’t the best way to save it.

I hope this article was helpful and don’t forget to share the article with your friends: Happy Riding.