Troubleshooting the Razor E100 Series Scooters

by James Dunham
Wild Scooter Parts

One of our highest selling products here at Wild is the E100 Control Module. It is also the number one returned item. I've personally tested all of the returns we received back and how many defective controllers did I find? None. Zero. This has shown me that there is a fundamental need for a good troubleshooting guide about these scooters. This guide is a targeted version of our How To Troubleshoot Your Electric Scooter article, as the Razor E1 series has some unique features that differ from most electric scooters. This article applies to all Razor scooters that start with E1 (E100, E125, E150, E175) as well as the E90 (except that's 12V). So let's begin.

In the video above I demonstrate how to check the components mentioned in this article.

Batteries and Low Voltage Cutoff

It surprises me that people often don't even think to check the batteries. Aside from tires and tubes, it's about the only other thing on the scooter that will wear out over time, so it's the first thing to check electrically. But just how do you check them?
When the battery on your car may be bad, you bring it to your local auto parts store. Unfortunately, not everyone can bring their batteries to our Denver office for me to test. Actually, that is fortunate - I'd rather not test batteries all day long. Luckily, a basic test can be performed by anyone and all you need is access to a multimeter to measure the voltage from the whole pack and on each battery. If you don't own or know someone who has a multimeter, I can give you a pro-tip - Harbor Freight sells a very cheap one that's more than good enough for the job. If you don't have a Harbor Freight nearby, RadioShack or your favorite home improvement store will also have them, or you can order one from our website here.

Once you have a multimeter in hand, it's time to get at those batteries so they can be checked. Remove the deck from the E100 scooter using an allen wrench, the back two will also require an 8mm wrench to hold the nuts on the bottom. With the deck off, remove the 2 phillips screws that hold the strip of metal going across the batteries. Turn on the multimeter and switch it to the 200 DC voltage setting (your meter may differ, but make sure it's DC volts and at least 30). Now find the white connector that goes to the batteries, it will have a thick red and black wire going in to the controller. Stick the red probe of the multimeter in through the hole on back of the connector on the red side to that it's touching the metal terminal, do the same with the black probe on the black side. You should now see a voltage show up on the meter. A health fully charged battery pack will show around 26 volts. A so-so or uncharged pack should still show around 24 volts, and a fully depleted pack may show as low as 22 volts. If you see anything less than 21 volts, then one or both of the batteries are completely shot as a single 12V lead acid battery should never be below 10.5V. What you can do at this point is put the probes of the meter on the terminals of each battery and see their voltages individually. A dead giveaway is often one battery will show a normal voltage while the other shows something extremely low like 4V. You could get away with replacing just the one bad battery, but your pack will only be as good as the weakest cell, so we recommend replacing both.

Bad batteries is one of the things that trip a lot of people up and has them thinking the controller is bad. See, the controller has a feature called "low voltage cutoff" where it will not operate below a certain voltage. This is by design to protect the internal electronics. For the E100 that cutoff is roughly 22.5V, below that and you won't even hear the click the controller normally makes when you turn the throttle. So if your meter is showing less than 23 volts from the batteries, this is likely the problem. If the battery voltage isn't abnormally low (below 21), try charging the scooter and testing again. What you want to hear is a click when you turn the throttle, as long as you hear that your batteries have enough juice to pass the low voltage cutoff. Should you find you need new batteries for the E100, Wild Scooter Parts sells both the individual batteries and the battery packs complete with wiring harness.

Kick Start Required

This one is pretty simple, but not many people know about it. Heck I didn't know about it until a customer told me. The E1 series scooters have a feature where they won't spin the motor until you've kick started it and are rolling at around walking speed or 3mph. I'm assuming this feature is to avoid burning out the tiny motor as most of the stress on a motor is accelerating from a dead stop. So what happens when someone gets a new controller, plugs it in and turns the throttle - the wheel doesn't spin. All you hear is a click from the controller and so people rightfully assume they received a defective controller. There is an easy way to remedy this and test the scooter without putting everything back together and kick starting it. Place the scooter up on a table with the back wheel hanging off so it can spin freely. Turn it on and hold down the throttle, then use your other hand to spin the rear wheel forward - the motor should then engage. I demonstrate this technique in the video above.

Backwards Brake Switch

If you couldn't get the wheel spinning using the technique above, there is one more possibility besides a bad controller or throttle that is unique to the E100. Most scooters come with a brake lever that includes an electric switch so that when you squeeze the brake it stops the motor from spinning. And with most scooter controllers including every other kind of Razor this disabling of the motor happens when the switch is closed or on. Thus you can disconnect the brake switch and the scooter will still go, you will just lose that feature. Not so with the E100, it's brake switch is wired backwards so the when you squeeze the lever it opens the switch, and controller disables the motor when there's no connection. This creates a potential problem in that if your brake switch has become disconnected either at the connector or maybe due to a cut or bad wire, your E100 scooter will no longer go. Checking this is easy though, check out my paper clip technique shown in the video above. You simply disconnect your brake switch (it's the 3 pin connector with 2 yellow wires) and bend and insert a paper clip so that it is connecting the 2 yellow wires. It should look like the following picture.

If the wheel now turns (remember to spin it up first as described above), you've found your problem. You can also use the multimeter from the battery troubleshooting to test the brake switch. Put the multimeter on the continuity setting where it beeps if you touch the probes together. Or if the meter doesn't have that, put it on the ohms setting. Now insert the probes in to the back of the brake switch connector so they are contacting the metal terminals. If your brake switch is good the meter will start to beep or you will see it go to nearly 0 ohms. Squeezing the brake lever should stop the beeping or return to infinite ohms (indicated by 0L or -1). Should you find the brake switch is indeed bad, Wild Scooter Parts can get you a new brake lever with cable fast!

Additional Troubleshooting

If the scooter still won't run and the batteries and brake switch checked out in the tests above, you can continue to troubleshoot the E100 as you would any other electric scooter. There are only 4 more connectors left on the controller - the motor, the throttle, the power switch, and the charger port. And since the motor not spinning is probably your problem, there's nothing to test there. Testing the power switch is easy. If it lights up it's working, simple as that. If not, we've got you covered.

The Charger Port and Charger

While problems with the charger port won't directly stop the scooter from running, if you can't charge your batteries will eventually become completely drained and you'll run in to the low voltage cutoff problem I described before. This one is pretty easy to spot however. If after riding the scooter you plug in the charger, but it doesn't begin charging (the light doesn't turn red), then you have either a bad charger or a bad connection from the charger to the batteries. The charger connects to the batteries through the charger port which connects to the controller and thereby the batteries. Most controllers don't have any fanciness inside them regarding charging and the charger port connector is a simple direct connection to the battery as indicated by the live voltage on the charger port. So if it's a connection problem, it will be in the wiring from the port to the controller.

Before proceeding, I will give you a safety warning. As I mentioned the charger port is just a direct connection to the battery even though it goes through the controller, it has live voltage! It's easy when trying to probe the port to slip and make a short between the positive and negative causing lots of sparks… And if you're wondering, yes I've made this mistake several times. Nothing like learning the hard way. So before you do anything, unplug the battery pack from the controller.

We are going to basically do a continuity test again like you did for the brake switch, so grab the multimeter and put it on the continuity or ohms setting. Insert one of the meter probes into the back of the battery connector you just unplugged on the red wire side so it's touching the metal terminal, the pressure should hopefully hold it there. Now take the other probe and touch it to the pin on the charger port that has a red wire and the meter should beep or show nearly 0 ohms. Assuming you had continuity, remove the probes and do the same for the black wires. If you didn't have continuity on both these wires, you have a connection problem, possibly your charger port.

If the connection from the charger port is all good, then I'm sorry to say, but the charger has probably went bad. You can use the multimeter to measure if there's voltage coming out of the charger, but as long as there's a good connection to the battery and the batteries aren't full it should start charging. Wild Scooter Parts has both the OEM Razor Charger and a faster 1.5A charger.

Razor Single Speed Throttle

The Razor single speed throttle is very easy to test as it is basically a DPST switch. These throttles will have 2 pairs of wires typically orange or yellow and brown. When you twist the throttle each pair of wires of the same color will be connected together. You can once again continuity test each pair with the multimeter. Insert the probes in to the back of the throttle connector in the holes for one color pair of wires. Have someone twist the throttle and the meter should go from "0L" to beeping or nearly 0 ohms. Do this again for the other color pair. If you didn't get continuity from both pairs of wire when twisting the throttle then it is likely bad.

Alternatively if you don't have a multimeter, you could use the paper clip technique to connect both pairs of wires together from the connector on the controller. Do this with the scooter turned off and lift the wheel off the ground before turning it back on. When you flip the power switch the wheel should immediately start spinning. If so and it didn't spin using the throttle, then the throttle is bad. Once again, Wild has the part you need.

The Controller and Motor

And finally, if all the things attached to the controller are good, but the motor still won't spin, then the problem must lie in the controller itself or possibly the motor. Motors rarely go bad, so at this point it's very likely the controller. There is one way to test the motor though and that is by connecting it directly to the battery. Be careful not to create a short when you do this.

I hope this article has been helpful in troubleshooting your E100 series electric scooter. As always, we'll be glad to help with anything you need, just contact us by phone at the number at the bottom of the page.