Melted wiring

[clem27]

Hello all,
I was riding my 95 tour back from Atlantic city today and the bike was doing great. Then the left blinker started staying on and the right would blink very quickly. I pulled over and the bike behaved very strangely. I turned the key off and the bike did not stop running. I hit the kill switch and it still would not turn off. I fiddled with the wires in the back and the bike died, but kept trying to start it self with the key turned to off and the kill switch on. I scramble to pull the main and it was all melted (15a). I got the pliers out of the emergency kit and it finally stopped trying to start. Any time I try to add the fuse back the bike tries to start, even without the key in. I noticed there are wires that have burned through the casing and tape that lead from the back of the bike to the fuse box. ANy suggestions on what went wrong or how to fix are greatly appreciated.















95 skoprion tour
13,000 miles

Thanks,
Matt

[DAVID THOMPSON]

one of the things that can happen is the starter relay from the battery shorted out in side its case
or something in the starter switch shorted

or a wire got hot then melted many other wires together...

dave

[clem27]

Dave, thank you very much for the reply. I don't know much about bikes but I will be sure to investigate that.

[Linegeist]

If my Tour is anything to go by, the East German wiring quality leaves a lot to be desired. I've worked on a bunch of Soviet Era machinery, and much of it suffers from substandard materials - the factories just didn't have access to the quality kit we take for granted (although the current flooding of the market with cheap Chinese crap is fast changing all that!!). The wiring harnesses in the 70's-80's-90's MZ bikes made in the former DDR is no exception. I have a 1981 VW Polo (restoration project) in my workshop, and its wiring's still perfect, while all the copper wiring on my Tour is turning green, furry and brittle, even though it's nowhere near as old.

I've had a few electrical gremlins with my Skorpion - sorted mostly by replacing lengths of rotting cabling and soldering-in fresh connections to replace the corroded mess the OE plugs have become. With hindsight, I suggest that a rewire on your bike will pay dividends in terms of reliability and peace of mind. It sounds like most of your wiring's shot anyway - and I'm not sure I'd want to trust what's left.

A full rewire is, in my experience, rather easier than grafting-in new circuits piecemeal - it's just a case of space, tidiness, logic and following the wiring diagram to the letter, using the old wiring harness as necessary as a reference, as you replace each and every wire in turn. I did a big Honda 4 years ago and it took me a weekend from start to finish - and cost me £20 for a donor Audi harness from a car breaker.

It's remarkably easy to make up a new harness using a written-off car loom, picked up from a breaker. My mate 'down the road' rebuilt his Ducati using the loom from a 2-year-old Merc. Beautiful quality wiring, more colours than you can shake a conrod at - and he had plenty of wire to spare afterwards!

[DAVID THOMPSON]

make up a new harness using a written-off car loom

quote above is what i would do
trying to keep colors same to help when repair is needed later

Dave

[clem27]

Thanks guys, I have a call into a European motorcycle shop just to see if they may be able to look at it. If not I may try to do as you said.

[clem27]

Update for any interested,
The European bike shop did not respond but I found a local mechanic that would work on it. He said my rear brake switch was shot that is where the short started. He replaced most of the wiring from the fuse box back and any wires that had the melted green goo.

I took it out and all seemed okay, when I went to switch the bike off, it stayed running. I had to pull the fuse or hit the kill switch to shut it off.

A week later the clutch cable snapped.

After waiting for a cable and fixing that, the bike was dead. Jump starting it works, but the bike will not hold the charge.

When trying to shut the bike off, the key does not work, nor pulling the main fuse which is strange. The kill switch does work.
Once it shuts off, it is dead again.

I'm not sure of this is all related to one wiring issue, or if I have a battery, ignition switch and charging issue.

Any and all help or suggestions are much appreciated.

[DAVID THOMPSON]

there is a group of drawings on the mzog yahoo groups by tony idle
if you can not find them there in the files section
text me and i will down load and forward them to you

sounds like you still have harness problems
dave
pm me a real email address

and where you located in the usa

[clem27]

After putting in a new battery, I have noticed a sort of pattern. If it is cooler out, the bike behaves normally.

Example: Riding 25 miles to work at 7am, bike is fine

15 miles at 1:30pm, bike will not shut off with key turned to off or out completely,must pull main fuse to get the headlight to turn off. After letting the bike cool off and replacing the fuse, the lights stay off.

In other news, after replacing my chain, a rear sprocket bolt decided to somehow back out of its place and smash into the swing arm, thankfully not while riding. How that backed out while sitting in the driveway after driving 30 miles home I have no idea. Hopefully finding a replacement bolt will be easy at the local advance or hardware store.

Feedback is welcome,
Thanks, Matt

[DAVID THOMPSON]

be careful of the quality of those bolts and do use loctite on them
and check the sprocket nut OFTEN

DO give that electrical system a very good eyeball inspection
and if your in a really hot area the handle bar switches can get very hot and there are very close contacts in them
power may be jumping inside them and back feeding things
dave

[clem27]

Thanks Dave, sprocket was an easy fix.

Wiring still having issues.
It seems if the bike is started, then I turn the key, it will shut off.
If the bike is started, and I press the brake and the light turns on, the bike will not shut off with the key, or even pulling the main fuse. The kill switch works, but when replacing the fuse the headlight will stay on. After leaving the fuse out for a while, it is ok to replace.

I will try to get a video of what happens

[DAVID THOMPSON]

relay sticking 19 on rt 125 30 on baggie?? 21 on 660 sport
the unit in mz rt 125 and traveller was very small and compact
and has failed on both
back current diodes 31 32 and 34 shorted or open

dave

[clem27]

I gave it one last shot and was still stumped, the intermittent brake is due to worn out contacts, not wiring issues so its unrelated to the problem. A buddy suggested the ignition switch, so I was looking online to buy a new one. I took the headlight off to look at the connectors and tried the key while fiddling with the wires just for fun. The bike turned on and off correctly. Looks like the connector for the ignition was a little loose. Hopefully that's the end of this.

[clem27]

Fuse blew after hitting a bump today. The bike shut off instantly after hitting the dip. I tried to replace the fuse and it sparked, even when unplugging my faulty ignition connector(not sure if that has anything to do with it). I took off all the body parts and gas tank and things look okay, no exposed wires or loose connections. I'm at a loss.

[DAVID THOMPSON]

look at tail lamp where wires connect to the bulb

my rt125 shorted out there one day when the lamp socket came apart
but it could be anywhere
dave