A new old guy

Local time
3:17 PM
Jan 24, 2022
Hi, I'm playing around with a pile of parts I got from a friend, including rear hub motor, a bunch of controllers, 2 decent batteries and a display but no pedal assist sensor so I bought one and tried to get working - no joy so far though. It's the typical low priced stuff but is all new. I thought it would be a fun conversion to my '94 Cannondale mountain bike. I understand a fair bit of electric/electronic troubleshooting and work quite a bit on cars, bikes and motorcycles. But this thing has me sort of stumped.

I'll post in the appropriate forum but wanted to introduce myself and say hello. I'm in OC California.
Thanks, my friend lent me his working bike so I can hook up and test each component against known good ones, which really helps. So far I've confirmed the hub motor and battery are fine.

He got two of them really cheap off some Chinese wholesale site a few years ago and had some problems. The seller thought he was a dealer and shipped him several things. I have 4 controllers, each with the same part number and with different wire colors / connectors coming out :rolleyes:

I ordered a PAS unit, the one I have is trashed. I understand the concept and functions of it, am getting ~5v at the controller on the plug which I think is the correct one - it has several 3 plug connectors and I don't want to mix up with throttle or cutoff switch (?). I will confirm today by double checking his unit (which is buried inside the frame unfortunately).

Welcome aboard. Sounds like you have taken on a real challenge. There a lot of DIY builders here don't fail to ask questions along your travels into the E-Bike world.
I hate PAS sensors and never install them on my builds. Throttle control is much more predictable.
I hate PAS sensors and never install them on my builds. Throttle control is much more predictable.
Yeah I can see why, I just have one of those old twist grip shifters and didn't want to fool around with what's working well. Not having much luck with the PAS at this point, the wiring is just guesswork with all the junk I have. I may just bite the bullet and get a set of stuff from one vendor that works together and use a throttle.
That would be the easy, but more expensive way to do it. I personally like these kind of puzzles, trying different wire combos. Last time I had to fit a new controller and LCD computer to my existing set up. Amost gave up before figuring out that controller to LCD wires weren't pinned correctly, even though they came from the same vendor. After repinning them, the bike came alive. If you have the time, I suggest you try it. Btw, in this set up, the throttle did not work until LCD was properly pinned and powered up.
Hi! I’ve bought replacement throttles, brake handles, and displays throughout the years. A few times I bought parts that have the wrong connection ends and don’t fit my controller. Like having a female instead of male end on my new part that connects to a female end on my controller. So I had to splice the wires and swap the female head for a male
Oops! My reply got cut off. I own 3 ebikes since I use them for work, all built from kits. Newest is 48V with LCD display. Other 2 are 36V with simple 810 displays, one a winter bike with studded tires. I live in Chicago. My 48V kit arrived with a full twist throttle. I prefer the half twist. So I tried swapping the full for the half twist and it wouldn’t work. I’m not sure if the throttles are voltage specific. They all look the same and don’t have voltage info on them. A new spare one wouldn’t work either. Either way, is your display turning on? Make sure that everything is of the same voltage, too. If I connect my display and hub to my controller and then connect the battery it will turn on, even without the PAS, throttle, or brake cutoffs connected. Do that, then try the throttle in different ports. PS. My controller has an extra 3-wire connection that PUTS OUT 12w of power for extra equipment and I bought a light kit and connected that. Maybe you connected your throttle to that? Just a thought.