ST1300 Windscreen switch stalls bike

Here is an odd problem that I hope someone else has run across and solved.

On occasion, when I try to raise or lower the electric windscreen at idle, the bike dies. If I hit the starter button it fires right up as if nothing is wrong. The bike runs great and the windscreen operates perfectly without noise or hesitation. Unfortunately, this is an intermittent issue, but it has occurred on three occasions over the past two weeks.

When the bike dies, it is as if I have activated the kill switch, no stumbles or misses; just completely shut off. The lights are not affected. Possibly related...the right front turn signal lights up but no longer flashes around the same time this first started happening, although I have replaced the bulb. The battery is fairly new and in good shape. I will spray some contact cleaner in the switch this morning just because I can't thing of anything else to do.

Probably not related - I have, over the past month - Installed new spark plugs, serviced the air filter, replaced the fuel pump, 2 new tires and rear brake pads, and run some Seafoam through the beast. The bike has just over 100K miles on it and I have owned it since 6K.

I am comfortable with pulling the plastic and the screen to troubleshoot but not sure what I would look for when I do. Anyone have any clues for me to run down?

Thanks

I'd open up both switch clusters (at each grip), clean out any moisture and debris... lotsa funny stuff happens when contacts in those switch clusters are dirty.

Have you tried activating the windscreen off idle ?

Try holding the rpm's @ 2k or more and see if something weird still happens.

If the windscreen works normally, it may be a low amperage/voltage problem causing the bike to die.

If it still stalls , it maybe a problem in the windscreen motor circuit .

Sounds like it may be a grounding problem due to the turn sig lighting up.

If you have he left side plastic off , check the green wire in the large connector for damage or corrosion.

Also i would try adding a ground wire from the battery to the frame to see if that helps . That would indicate a ground problem.

Great,

I removed both of the switch housings on the handlebars and ran a load of contact cleaner thru all of the switches and wires. They looked a little dusty in some areas, but this is the first time they have been apart since they were put on in Japan back in 2005.

I saw no hints of corrosion. Everything seems to be working now, but in the back of my mind I know that the issue has been intermittent. So I am still skeptical. I have plans to go to several STOC's out of state this Fall so I want a warm fuzzy feeling that things are OK.

Off the garage to try some of the other suggestions. I would like to find a bad connections or corrosion so that I know I have "fixed" the problem.

Thanks for all of your fast responses.:bow1:

OK here is where I stand now...

Completely removed both switch clusters, 2/3 of a can of contact cleaner later, they were all spotless. I then re greased the moving parts with dielectric grease since any grease that had been in there was now long gone. That part is done - cleaned and put back together.

Ran an (additional) 10 gauge ground wire from the neg terminal on battery to the frame.
Cleaned, tightened and greased the connections to the right side front turn signal - that now works perfectly so there must have been something loose in that connection (yea!).

Tried to recreate the cutout issue both at idle and at 2,500 rpm. I could not recreate the cutout.

So, the old girl is running and I cannot recreate the (intermittent) problem. Only time will tell if it is really cured or not, but at least I will know now where the problems are not. I will whisper a prayer to the Honda gods and ride the machine for a while hoping that the issue is permanently resolved even though I never really found what I would call an obvious fault.

Thanks again for all of your suggestions and expertise. I appreciate you taking the time to respond and help.:bow1:

I didn't see any indication that you've already done it in the thread above. Apologies if you have....
As V8-7 suggested above, and I'm suggesting here again.... Check the ground wire/pin in the big 24 pin connector behind the left mid-fairing. See post #18 in this thread for a picture and better description.

That little ground wire pin carries the ground return for everything in the front-end of the bike.
The critical piece here, as it relates to your problem, is the bank angle sensor - which subsequently supplies the ground return for the bank angle sensor relay. If the bank angle sensor relay doesn't stay engaged, then there will be no power supplied to the FI system. Bottom line - as soon as the bank angle sensor relay opens, it'll be like someone hit the kill switch.

That little pin in the 24 pin connector has to carry a lot of current. I've measured it at something like 15 amps when the wind-screen motor is activated. If there's not a really good mechanical connection in that pin's male/female contact points, then there will be an increase in resistance (a couple ohms is all it takes) and an associated rapid rise in temperature. As the temperature rises, the resistance rises. Eventually that connection's resistance rises to the point that it can no longer support the flow of enough current to keep the bank angle sensor relay engaged. Thus, as soon as that happens, the bank angle sensor relay opens, and the bike shuts off.

It sounds like you've already done as V8-7 suggested above, and added a ground wire from battery-to-frame. I would also suggest adding wire from one of the ground points on the front sub-harness (say the green wire on one of the headlight socket/connectors) to the frame, or better yet, the negative battery terminal. Essentially providing a parallel path back to ground for everything in the front sub-harness. That will take a lot of stress of that poor little pin in the 24 pin connector.

EDIT: As long as you're at it, you should;
- Check for chafing on the wire bundle that carries the wires coming from the left handle-bar switch pod. See here for more details.
- Check the front sub-harness ground concentrator block (it's up in the nose, just back from the right headlight). See here for pictures.

EDIT2: Interestingly, not long after I posted this response, one of our Aussie brethren posted a testimonial outlining the exact same thing. See here

PDFURTH V8-7 and others,

I have not checked the 24 pin connector. but I will have a chance to do that tomorrow night. Thanks for taking the time to respond and the links. I will check the connection and be sure it is tight. I will also try to sort out an additional ground for the front electrics.

When I open and inspect the 24 pin connector, does anyone recommend applying a small amount of dielectric grease inside??

Thanks again and I will post up my results for everyone who has an interest.

brandanharmon said:

I then re greased the moving parts with dielectric grease since any grease that had been in there was now long gone.

Click to expand...

Dielectric grease doesn't conduct electricity. A 12 volt circuit can operate when switches make contact but the grease will increase the resistance. Best to use contact lube on switches and dielectric grease to seal the wires and housing on the outside. Some folks use it to seal contacts inside connectors, but that's not it's purpose.

I tried a little of everything and believe that I have solved the problem with your help.

I opened and cleaned the 24 pin connector on the left side of the bike. I opened and cleaned the grounding bock in the front of the bike under the nose fairing. I also ran an additional ground from the headlight assembly to the frame. Previously I had added a secondary ground from the negative terminal on the battery to the frame. I inspected and cleaned every wire bundle I came across. I found no chafing but did re-tape and zip tie everything back securely.

The bike has not exhibited any of the intermittent stalling in the past 500 miles, so I am ready to declare victory with this issue.

If I had to guess where the real issue was, I could not say for certain. One thing that I "think" I notice is that the headlights seems to be brighter although I have no real way of measuring or comparing the before and after. In any case, the headlights have me leaning towards a grounding issue somewhere.

Over the years I have increased the wattage in the headlight bulbs and spliced a GPS electric feed into the front end electrics. Between that increased load, and 100K miles of dirt/dust buildup around the connections that may have been just a bit too much for the OEM grounding system. The wiring strikes me as being pretty light gauge but I am by no means an electrician.

Thanks again to everyone for their help, suggestions and links. I really appreciate your time and expertise.