Mirage 1200TS electrical issue

L

lawrence

Hero member
Location
Idaho, USA
I was optimistic when I declared my install of the new RR was a success. It started immediately at that time, but when I later tried to give the bike a proper road test, I never made it out of the driveway. After a mere 10-12 hours, I located the problem. There was a old fried connector that was in the process of failing, giving intermittent power to the coils. I replaced that and the bike again starts on the button. However, I discovered that I'd introduced yet another problem to the system: the engine does not turn off with the key. It only turns off with the kill switch. It is now possible to turn the lights on without the key as well. I've no clue what I've done to screw this up. I need some ideas on where to start sorting this. Thanks.
 
lawrence said:
However, I discovered that I'd introduced yet another problem to the system: the engine does not turn off with the key. It only turns off with the kill switch. It is now possible to turn the lights on without the key as well. I've no clue what I've done to screw this up. I need some ideas on where to start sorting this. Thanks.
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It sounds like you bypassed or bridged the key switch? Track the power cable from the battery to that key switch. Does it get connected to anything other than the wire that goes through the fuse to the switch?
 
I encourage folks to learn about electrics and do their own wiring, but if it all goes wrong it's very optimistic to expect someone else to sort electrical problems via internet. Plenty of people on the forum (including myself) are happy to offer suggestions, but they're little more than guesswork. There are so many possibilities that you really need to be there with a multi-meter or other diagnostic tools to track down a fault.

If you get yourself into a pickle, the best option is to seek help from someone nearby with electrical know-how, who can come to your place and go through it with you.

Keep asking questions by all means, but unless it's something really obvious, don't have any expectation that we can zero in on the right answer first time.

I agree with arancia. You've somehow bypassed the key switch, but how you've actually done that is a mystery that I seriously doubt anyone can solve for you via internet. Especially on a 40 year old bike that's probably had many people fiddling around with the electrics.

If the only things you've done are to install a new RR and fix a dodgy connector, then they should be your starting points for diagnostic investigation. I suspect you've somehow cross-connected the switched ignition feed to the kill switch with a live 12V feed from the battery.
 
Dellortoman said:
I encourage folks to learn about electrics and do their own wiring, but if it all goes wrong it's very optimistic to expect someone else to sort electrical problems via internet. Plenty of people on the forum (including myself) are happy to offer suggestions, but they're little more than guesswork. There are so many possibilities that you really need to be there with a multi-meter or other diagnostic tools to track down a fault.

If you get yourself into a pickle, the best option is to seek help from someone nearby with electrical know-how, who can come to your place and go through it with you.

Keep asking questions by all means, but unless it's something really obvious, don't have any expectation that we can zero in on the right answer first time.

I agree with arancia. You've somehow bypassed the key switch, but how you've actually done that is a mystery that I seriously doubt anyone can solve for you via internet. Especially on a 40 year old bike that's probably had many people fiddling around with the electrics.

If the only things you've done are to install a new RR and fix a dodgy connector, then they should be your starting points for diagnostic investigation. I suspect you've somehow cross-connected the switched ignition feed to the kill switch with a live 12V feed from the battery.
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It would be impossible to refute what you are saying, Dellortoman. I also get what Arancia is saying. But that does little to clarify how I got in this pickle. I'm the second owner of this machine. The wiring is not so terribly molested and is OEM except for a headlight relay, a DIN plug receptacle and heated grips, all installed myself. (well, there is the MotoWitt ignition, but....) Those accessories are wired into an accessory fuse block. In the course of swapping the RR I changed only the five wires that are on the Shendigen RR. I opened and cleaned other connectors in the loom, it's true, but I did them one at a time to help avoid a reconnection error. You can see why I'm perplexed, given that process.
BTW, I relied on the schematic in the owner's manual for my Mirage, and discovered the color codes on the bike's wires do not reflect what's in the manual. That revelation really brought back memories. Many decades ago I wrecked my American Eagle 750. The headlight shell was ruined and all the wiring within had to be redone. I discovered the wires in the loom were not color coded at all! I couldn't afford the BMW headlight shell, so I replaced it with one from a Japanese bike. What a pisser that was.
I can foresee me spending a LOT of time chasing this problem, now that riding weather has returned.
 
Yes, wire colours not matching the factory wiring diagram is another common problem. I've come across that with Italian bikes myself. Seems the colour specs in the manual are just a vague suggestion to the guys who actually do the wiring! One of the reasons I tell people not to rely too much on wire colours.

If your fault only appeared after you fixed the fried connector, there might be a clue there.
 
Does it have a red warning light on the dash? Just had exactly this on the rewire of my sf2. Charging lamp was backfeeding power to the ignition. You could only turn off with the kill switch. A diode in the line to the globe fixed it.
 
The 750 twins have a DC generator so the charging light works differently. It's part of the DC voltage regulator system.

The triples have alternators and rectifiers. A whole different kettle of fish. Who puts fish in a kettle anyway?
 
That you managed to sort the older bike shows that you can find your way around wiring. Two basic things. The main feed to the ignition switch is on any bike pretty much direct from the battery via a fuse, should be easy to check if this is wrongly connecting to somewhere. On many rec regs (I don't know yours) there is a B+ terminal pretty much direct to the battery, and a switched + to power the diodes. If these are on the wrong terminals you could get battery power into the system.
 
I know it's quite a trip from Idaho to Arizona but if all else fails put it on a trailer and bring it here and we'll figure it out!
B&B for Laverda owners and diagnostic services here at a very reasonable cost.
 
Number one rule in problem resolution for computers that were just updated is to review your last change. If you can't resolve it then you back out the change, re think it and put in the updated change. So the RR and any wiring changes....isolate each change if possible. Even if your not an expert in Laverda electrics this helps keep the process simple.
 
Sorted! :)
I have decided the problem arose due to the differences between the fried SH350 RR and the new Shendigen MOSFET RR. The old had 6 wires; the new one has 5. My mistake was to assume the 6th wire needed to be connected to the battery + terminal, as the old RR was wired. Wrong! I pulled it from battery, insulated the connector and the system seems to be working now just as Giuseppi intended. ;)
If I may be philosophical for a moment, I will say I'm fortune this didn't leave me stranded far from home, rather than in our driveway. In the course of sorting this problem I found many connectors and ground points that had been neglected to the point of posing a real threat to reliability. I found enough verdigris to make a salad.
Owners who are nursing an old, unrestored Laverda will find servicing the wiring loom time well spent.
As always, I'm grateful for all the advice given by members here.
 
Well, if you're confused, you are in good company. The "6th wire" is in the OEM loom. It was previously connected to the battery; I reconnected it when I fitted the new RR. That seems to be the source of the problem. Beyond that, my takeaway is that I need to find a local motorcycle electrical guru. If I don't have one to keep a close eye on me, I can easily get into trouble. I can swap out an old (non electrical) part for a new one, but beyond that nothing is guaranteed. :( I don't think there is another Laverda in the state where we live. No mechanic will touch mine, it's such a rare bird.
 
Re Laverda mechanics in US. Try see if there is an antique or classic motorcycle club in your area. These guys might help or know someone who can. Many of the tasks maintaining a Laverda or fixing a problem are similar to any old bike of the era. This Forum can help a knowledgeable wrench with any Laverda specific issues.
 
lawrence said:
Well, if you're confused, you are in good company. The "6th wire" is in the OEM loom. It was previously connected to the battery; I reconnected it when I fitted the new RR. That seems to be the source of the problem.
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Ah, OK. That makes perfect sense. The "6th wire" in your wiring harness was the voltage sensing wire that's connected to the switched side of the ignition switch. By connecting that to the battery, you're basically bypassing the ignition switch.

If you wondering what to do with that wire now that it's redundant as a voltage sensing probe for the RR, you could use it to power some other accessory, like heated hand grips, a GPS or a voltmeter. It'll only be energised when the ignition switch is on.
 
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