How to test throttle..for Dummies

medusa569

100 W
Joined
Sep 17, 2010
Messages
161
Location
Washington DC
I' d like to ask how exactly does one test the throttle pins for voltage. Please outline placement of the multimeter probes. What are the negatives ( if any ) of switching pins trying to match the wires?
 
Many throttles have 4-5V between the red and black wires use the same colors for the leads on your meter to measure it with your controller on. Then move the red multi-meter lead to the other color wire often green and check for variable voltage of around .7 to near 4V as you actuate the throttle. Some throttles have extra wires for battery charge state these are not needed for the throttle to function.
 
Connect it to your ebike tester using the 3 clips on the left side red/green/black , not the blue/yellow/green which is for testing the motor phase wires. Turn the tester on and the single led that is lit will turn off and then come back on as you turn the throttle to know that the throttle is functioning properly. It's easiest to slide one or more of the spades out of the connector to clip on the alligator clips of the tester. I use a very tiny allen wrench to push the locking tab to the side the enable the spade to slide right out.

The wire colors are often different from the throttle itself, so once you figure out the correct ones, and the wire colors don't include red and black for +5V and ground respectively, mark them with colored electrical tape to save yourself time later down the road. When putting them back in the connector, make sure they match the controller, which has a standard of +5V and gnd on the outside with the return for the throttle sense in the middle. The controller side is easily determined with the multimeter set on DC voltage and the controller turned on.
 
You can't test it unless it's powered. If you're lucky, you can get your voltmeter probes onto the pins in the three-pin connector while it's connected to the controller. If not, you need another way of getting 5v to the red(+) and black(-) wires. You can use a 5v phone or USB charger. Then you measure between the third wire and the black to see the changing voltage. If you want to test your controller, you can use a 10k potentiometer: The red and black pins to the outer two on the pot and the third(signal) wire to the middle pin on the pot. You have to turn it down to zero before the controller will respond because most controllers have this safety point programmed in.

As has been said, some throttles have LED lights and/or a switsc in them. Normally, the throttle wires will be three in a bunch, or look for the red and black wires and the one next to or between them. In some installations, the switch on the throttle disables it, so, if you have one, check that it's switched on.
 
Medusa has an ebike tester, so the process is super simple for him and the tester supplies the voltage to the hall sensor in the throttle, and no it won't hurt anything Medusa if you don't get the wires wrong.
 
Thanks to all who responded....I think my throttle is fine....actually I tested 2 so I'm back to being stumped. Dead system...battery reads good... throttle /halls and phases test good on Lyen tester..but when I hook it up to controller to test ( using the last 2 groups on the right of Lyen tester I get no action. I've tested 9 different combos and no revalution of lights on the tester. Hooked everything up to bike and no noise or movement there. This is my first using controller that need a pigtail wire to power it. when I measure V with my DMM on each black and red combo I get 40 v. readings. Last night I installed a rocker on off switch on the smaller red wire...connected battery to controller...powered on battery and then switched on
smaller controller feed...still nothing. Any thoughts...I've been trying to trouble shoot for 2 weeks !!
 
I'm sure you've done this, but just to make sure: Check that you've got 40v on the controller side of the rocker switch. Make sure the brake switches aren't disabling the power. Unplug them, and if it works it should be easy to figure out which one needs sorting. Also, it's worth checking that the 40v doesn't drop to zero when you try to power anything. I've seen one battery that showed 40v, but as soon as I tried to draw any current, the BMS prevented it from giving any.
 
Back
Top