Red Wire, what now …

increasing

increasing

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Joined
Feb 28, 2025
Messages
156
Location
Oslo, Norway
Bike
ST1100AX
Recently bought an ST1100AX which I am in the process of doing a full service with all recommendations from the "ST1100 - Basics / Buying Guide" including the "Red Wire By-Pass Mod (ST1100)".

I have ridden 180 kilometers with the bike which runs well and all the electrical works well, but ... was a little surprised when I checked the "Red Wire" ... I found the connector housing in the tool bag ...

Take a look at the pictures, there are a lot of threads here on the forum on this problem but what is the latest and what is the best thing to do? What do I have to buy and what should I buy to get this as tidy as possible with a solution that is good

Red Wire By-Pass Mod ( ST1100 ) *

Red Wire By-Pass Mod ( ST1100 ) *
www.st-riders.net

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Follow the wires back into the harness. The core of the current wires will probably be black some way back, rather than copper coloured. Find some that isn't. Splice in the new connector (I'd want longer leads than that in the photo above - I'd probably replace it my own cable and new terminals.) Don't cut the cables to be the same length - I wouldn't want my spliced joints to be next to each other.

Before you start, make sure that you know what colour wires go into which slot in the connector.

Don't do this with the battery connected. One of those leads is live from the battery - so disconnect the battery at both terimals and remove it from the bike.

I'd be looking to remove the red wire by-pass. I may be wrong, but that does not appear to be fused before it reaches tha main harness.

There are two likely problems - that area of the bike is not protected very well from road spray. It gets wet.
Another is that that lead is already up to capacity on the equipment that it turns on. Often people do not think about this when adding new equipment. If new equipment is added to existing wiring, how is the cable, the terminals and the connector housing going to cope with the extra current and the extra heat.

The red wire bypass cures the symptom. The problem doesn't go away - as is evident from your photos of the destroyed connector.
So go hunting for other add-ons that have been wired into the bike.

Then think about how you could protect the connector from road spray. The side panel doesn't manage it.
 
Thanks for your help both of you :thumb: A trailer hitch, high brake light on the top box and hot grip handlebars have been installed. All of this is disconnected and I don't want it, if I want power for the GPS it is 12V with a 5A fuse behind the battery.

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My original plan was to do a "Red Wire By-Pass" but now I have to get parts first from UK to repair the damage so I can install a "Red Wire By-Pass" at the same time before it goes back on the road. Waiting for parts for the rear wheel splines too, the three o-rings :)
 
increasing said:
My original plan was to do a "Red Wire By-Pass" but now I have to get parts first from UK to repair the damage so I can install a "Red Wire By-Pass" at the same time before it goes back on the road.
Click to expand...

Your choice - but remember that red bypass lead is going to carry 30 amps - and it is always live - because you have bypassed the fuse. And your terminals, connectors and wirong all need to be capable of handling 30Amps

But there is really no need for it - the proper components are well capable of handling the current and the environment. They fail when additional equipment is added without giving any thought of where the power is coming from. "Oh - I'll just tag it onto the lead that powers the rear lights" attitude - not thinking that it all has to go through that connector.

A similar sort of thing happens with a multiway connector on the ST1300. Well capable of handling the power that they were designed for, but not a great deal more.

Fit the new relay. Patch in the wires. Apply electrolyte grease to the contacts. And check the bike for the accessories that have been added that might have caused this failure.

If you need to add other accessories, take your own fused power from the battery through a relay which is turned on by the accessory connector that you have found tucked away.
 
Sunday Rider said:
I've done the red wire bypass and had it fail on me once. I carry an extra fused wire to do it again, just in case.

As @jfheath says, it doesn't solve the problem.

To solve it, have a look here: http://www.st-riders.net/index.php?topic=3643.0

Even more involved but a bit different is: http://www.st-riders.net/index.php?topic=12377.0
Edit: thanks to @jrp for the second one
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Here is the link to the more readable version on this site:

Ignition Relay Bypass Mod - ST1100 ABS | ST1100 Related

I'm am planning a long trip next year that will find me in the boonies from time to time, so I figured it was time to address the red wire issue that plagues the ST1100. It appears there are two approaches; the "red wire bypass" and the "ignition relay bypass". The "red wire bypass" really...
www.st-owners.com www.st-owners.com
 
It seems that in the past somebody replaced the terminals. Looks like aluminum terminals, maybe the crimping they did is not right, so it was overheating. They should have use brass terminals, and a very good crimping tool. Good that you are replacing all the socket.

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jfheath said:
- that area of the bike is not protected very well from road spray...
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Either this, and/or chemicals/contaminants from road spray and/or washing detergents...
(dunno the legal situation in NO, but down here washing a vehicle on private or public property is prohibited, so folks have to abuse their vehicles with the high pressure kits/Kaercher installed in the designated washing areas at gas stations... and the chemicals added to the constantly "recycled" water there are absolutely aggressive...)

Those "automotive" crimps shown are inadequate, I demise those "colorful" Bosch system things made of soft anodized copper...
You need the OEM style double crimp made of brass; and not the flimsy, cheap ones either...

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And a designated, quality crimp tool as well...
 
increasing said:
I get provoked when I see these blue/red cable lugs. I consistently use the original ones with soldering and heat shrink tubing over them.
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hmm... me personal not a fan of the soldering thing either...
You won't find such anywhere in OEM industrial, mechanical or automotive wiring...
The solder gets sucked up between the strains, making that piece of wire hard, prone to crack under vibrations...
 
increasing said:
Recently bought an ST1100AX which I am in the process of doing a full service with all recommendations from the "ST1100 - Basics / Buying Guide" including the "Red Wire By-Pass Mod (ST1100)".

I have ridden 180 kilometers with the bike which runs well and all the electrical works well, but ... was a little surprised when I checked the "Red Wire" ... I found the connector housing in the tool bag ...

Take a look at the pictures, there are a lot of threads here on the forum on this problem but what is the latest and what is the best thing to do? What do I have to buy and what should I buy to get this as tidy as possible with a solution that is good

Red Wire By-Pass Mod ( ST1100 ) *

Red Wire By-Pass Mod ( ST1100 ) *
www.st-riders.net

IMG_3628.png

IMG_3629.png

IMG_3632.png

IMG_3633.png

IMG_3634.png

IMG_9090.jpeg
Click to expand...
Your photos show the cause of most electrical failures on enclosed bikes.
Corrosion.
It's obvious at connectors, not so much at all the ground points. I inspect mine several times a year.
 
increasing said:
I get provoked when I see these blue/red cable lugs. I consistently use the original ones with soldering and heat shrink tubing over them.
Click to expand...
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www.easternbeaver.com

Wiring Tools

High quality crimping and wiring tools from Japanese, European and American makers. Built to last a lifetime. Terminal extraction tools.
www.easternbeaver.com
 
ST1100Y said:
hmm... me personal not a fan of the soldering thing either...
You won't find such anywhere in OEM industrial, mechanical or automotive wiring...
The solder gets sucked up between the strains, making that piece of wire hard, prone to crack under vibrations...
Click to expand...
That is, it is best to use the press tool posted by @ddiez :thumb:
 
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