As mentioned in my previous thread the lights and braking regen on my 2018 Zero S with PT started failing intermittently for a couple of rides before finally calling it quits. I checked the DC-DC fuse and it was OK. So I ordered a new DC-DC converter from AF1 Racing for $365. While it was listed as a "special order" the part arrived within just 2 weeks, which I thought was good service.
Last night I and my son-in-law spent 2.5 hours removing the old component and replacing it with the new one. The job was a big pain as the component is buried under a mass of large orange wires that could not be moved aside and had to be worked around. Here are a few comments regarding this project:
You first have to remove the seat and then the "tank" cover and both side panels covering the battery pack. Lots of little 2.5mm hex head screw to remove along with two Phillips screws. Then you can remove the frame Y-brace to gain access to the location of the MBB and behind that the converter. You need to pull aside the fuse box and unscrew the MBB module from the equipment frame and pull that aside to the left of the bike. That gives you access to the screws that hold the DC-DC converter to the equipment frame. After removing its four bolts you can pull and wiggle it vertically up past the snake nest of wires to remove the old component.
Then you can reverse the procedure to install the new converter, replace what bolts you can actually reach to reattach the converter to the frame and then reinstall the MBB with two screws to the frame and shove everything back into the inside of the chassis. It really helps if you have access to a 10mm ratching box-end wrench like a Gear Wrench. Also a tiny ratching L-screwdriver that uses a hex-head driver is a real help.
But it is not nearly as easy as it sounds. All of the bolts and screw that attach the MBB and the converter to the equipment frame are very hard to locate, access and to unscrew. And they are much harder to replace and to get threaded into the frame threads. Frankly, we could only replace about half of the securing bolts before we finally gave up and decided that was enough to secure the components in place. Besides, everything is so jammed into the bike that I doubt they would come loose or shake even if they were not screwed into the frame. Anyway, the lights come on, the horn works and everything is back to normal again, although I do have some leftover bolts lying around.
I just hope I never have to replace another DC-DC converter again.
One thing that is confusing to me is why the DC-DC converter works to change 80V to 13.4V? Since the bike's battery pack runs at 115V, where does that 80V come from?
Attached are captioned photos to help illustrate my comments. Unfortunately, things were so jammed in place that I could not get photos of the location of the screws that secure the equipment that needs to be removed. I will need a couple more posts to attach all of the photos.
I hope this is some help to anyone needing to replace that converter in the future.