Modern Vespa

Just rebuilt my 1980 P200e from the ground up. All new wiring except the horn/hi beam switch and the turn signal/off/run switch as they seemed in good shape. I am using the original ignition switch.

Original CDI, Resistor and Flasher. When I turn the ignition on the main fuse blows. I have seen other posts on this topic, but as I have a new harness I doubt I have any bad wires in the neck of the Vespa. Any body have any suggestions?

Would having an improper ground on say the front left turn signal cause this fuse to blow? If so maybe I need to go around and make sure the paint I took off around those grounds was aggressive enough. I may have been too delicate not wanting to mess up my new paint job.

I will add: 1800 original miles. The existing electronic modules seem in pretty good shape but they are 40 years old.

Thanks in advance! DP

When you say "improper ground", do you mean bad/no ground (not going to blow a fuse) or grounding of a wrong/power wire (will blow a fuse)? Sounds like B.

https://www.scooterhelp.com/electrics/pages/VSX1T.p200.html#euro_after

I meant if I don't have a ground on say the Right Blinker, it just won't work, but it won't cause the fuse to blow, correct?

One last question, should the turn signals and speedo lights come on without the engine running?

I am asking because I think I found the culprit. Appears someone, probably me when trying to get old electrical tape of stripped the cable housing on the line from the battery to the fuse holder. i taped it up with electrical and now when i turn the bike on the fuse holds and I can beep the horn, but nothing else works, granted I only have speedo bulbs and the front turn signals in place. I do not have the rear cowls on yet


Thanks everyone for the responses. I may jumped the gun on this. I read another post about start inspecting the wire from the battery to the front and I immediately found the issue. I added a pic of the bike as so many folks have helped me get to this point.

DP

Looking good! Good ground connections are a must. I share your concerns about messing up new paint. My P125X is in the paint shop right now! I have been thinking of what is the best way to carefully remove paint around bolt holes for making good ground connections and make it look good. I want to remove paint in a circular pattern that would be hid by the star washer and nut.
So here is my idea to accomplish that. I hope I can explain myself clearly. Find a threaded stud small enough to pass through the bolt hole where a loop terminal is to be used for a ground connection. Find a star washer nut to fit the stud. Double nut the star washer nut so that there is 1/2" of stud length beyond the star washer side of the stud. This length of stud will be inserted into the bolt hole and will act as a pilot guide as you spin the other end of the stud slowly in a cordless drill or by hand. Slowly insert the spinning stud till the star washer makes contact with the paint. Keep light pressure on the paint and go slow. It should remove a nice circular section of paint. Back the stud out of hole and install turn signal ground wire using the same size star washer. Done. I need to put one of these together and test it on painted sheet metal.

Hec

on a side note, it looks like you have the left side cowl clasp installed on the right side of the frame.

Good eye ..

KTM uses what they call a "contact washer" in certain areas on the frame for grounding. It's essentially a M6 beveled washer with sharp teeth on one side and a serrated(?) pattern on the other.
Part number is KTM 58411098100


The number on the package isn't the part number. Google search KTM 58411098100

Thanks for catching this, yes very good eye. I was getting ready to put the tank in today so this is a huge cacth. I appreciate it.

DP

I put the cowls on, I had the the Cowl Hooks installed correctly, must have been the angle of the pic. But I appreciate you bringing it up, I am glad I dry fitted the cowls before putting the gas tank in.

DP

He ain't wrong, the levers are installed incorrectly. But if you want to go against the grain, so be it.

I would say no. The light is either going to work or not based on completing the circuit.

You have DC power going to ground somewhere.

Hmmm...I am not trying to go against the grain, I appreciate everyone's feedback. See pics, I can't see how reversing these would work? Do you gusy think I should still reverse them?


Full Shot

close Up

Here is a pic of mine. I took this pic before disassembly.

Hec


Right Cowl Latch


Last edited by Hec In Omaha on Tue, 14 Mar 2023 14:23:24 +0000; edited 1 time

Ah...so the little handle goes down not up....Okay maybe I do need to swap them...I will play around with it. Thanks for the pic. This is my first rebuild ever of a two wheeled vehicle so I am learning as I go.

Okay thanks everyone, I fixed the ground out issue and I also reversed the Cowl hooks. Makes total sense for the handle on those to point down to keep your pants and things from getting inadvertently hooked on them. I could not visualize that until Hec in Omaha sent me that pic. Thanks Hec. Im a visual learner ;o) .....or just dense.

Glad to help! A picture is worth a thousand words right? Don't forget to clean off any paint on the brass contact where the cowl latch makes contact with the cowl. This is the ground contact for the rear turn signals.

Here is another 1,000 words for ya!

Hec


Brass contact on Cowl

Thanks I did clean the contact points off already, should be good to go!!

Just wanted to thank everyone again for the guidance. I must have installed the flasher wires incorrectly. Did not realize there were letters (P,X,L)on there that mapped to the wiring diagram and must have reversed a wire when I reinstalled. I corrected it and all my lights work great now. Appreciate all the replies!