2012 Buddy 170i fuel pump not getting power from battery

[NinjaMunkee]

(Apologies in advance if this has been addressed, but I searched through all posts within the past couple of years for "170i" and have not found somebody with these symptoms.)

My 2012 Buddy 170i occasionally would stall (i.e., the engine would die) when going, e.g., it has happened several times at between 20-40 mph. After a few of these cut-outs, the scooter would not start. I hired a scooter mechanic on Craigslist who came to troubleshoot the problem, and this is what he found.

He checked the ignition, battery charge, and fuel tank and deemed all to be okay.

He isolated the problem to the fuel pump not getting power from the battery by doing the following. First, he noticed that the fuel pump was not priming when turning the ignition to the "on" position. (Normally, the fuel pump will make a low but clearly audible buzzing noise when the key is turned to the "on" position without cranking the ignition.) Second, he checked the three main relays, but he wasn't able to figure out whether they were okay or busted because (a) they are opaque, (b) they are not labeled, and (c) Genuine's wiring diagrams are laughably inadequate. Third, he was able to consistently get the fuel pump to prime (i.e., make the low buzzing noise) by directly connecting power with wires to the (not sure what the proper term here is) positive and negative relay terminals just in front of the taillight.

In view of this, he surmised that the issue was with power getting from the battery to the fuel pump, but he indicated that without a proper wiring diagram, troubleshooting the issue would be a nightmare, as one would have to effectively deconstruct the entire bike, retrace the electrical lines, and test all points between the battery and fuel pump.

Has anybody seen this issue and have pointers on where to look first? Thanks in advance!

[Stanza]

So for the 170 there are a couple things that would cause the pump to not power on. The first and easiest to fix would be a bad fuel pump fuse. Under your seat bucket, or under the front plastic (I can't remember which) is a group of three fuses. The one for the fuel pump is hair-thin, and can break from vibration without appearing broken. Swap out all three, and you may solve the problem.

Option two is the tip sensor, which is under the front plastic. If the bike tips over, it cuts power to the fuel pump. If the sensor has failed (typically they don't, but for the sake of argument), you will not get any power to the fuel pump.

Option three would be a bad fuel pump, but you can easily diagnose this by checking for 12v DC at the pump socket.

[NinjaMunkee]

Thanks, Stanza. This is helpful. For option 1, the fuses, under the front cover, are all fine under a flashlight. For option 2, I'll check this one. For option 3, I don't think it's a bad fuel pump, since it primes every time it's directly powered, but only sometimes primes when connected to the battery.