91 ST1100 Ignition switch (?) problem

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Apr 13, 2015
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Fredonia, NY
Hello!

I have a 91 ST1100 with ~60k miles on it. I'm having an interesting issue. I put the key in and turn it to the start position and I get no lights on the dash. However, if I turn the key ever so slightly back to the left, the dash lights come on and I can start the bike. If I take my hand off the key it goes back to full start position and the bike dies. Bad ignition switch?
 
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Mellow

Joe
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Sure sounds like it, can't remember anyone mentioning this specific one before but my memory... ah... what was I saying? Anyway, maybe someone else will jump in.
 

Mark

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A shot in the dark:
How many keys on the key fob?

If you have a bunch try it with just the ignition key...
 
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jwumpus
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I tried it with just the one key. Nada. This may or may not be unrelated but the night before last I left the key on and ran the battery completely dead. I then jump started it with my car. No problem there. Rode around for 20 minutes. Had to get another jump because the battery hadn't charged enough. Got home, took the battery out, put it on a trickle charger. Probably unrelated but that's what previously happened before I came out this morning and had the aforementioned problem with starting.
 
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May be as simple as collected dirt/dust in the switch. Cleaning and relube would be my first step. The face up positioning dosen't help! My98 with 78k, has been a Lil twitchy too and I'll be doing this during this winter's maintance session
 
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It IS a bad ignition switch. I had exactly the same thing on my '95, but after about 100,000 miles. The contacts wear to the point of no contact when in the on position, but a slight turn of the keys lights everything up, just as you described. Cleaning will do no good. I tried that, but if it DID work for you, do you want to risk being stranded somewhere if it goes again?

Order a new contact base from Honda and change it out. You will need a couple of Torx head sockets - one of them a "safety" Torx, to get the thing off.
 
Joined
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2000 ST1100 ABS TCS
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004
Worn ignition switch, and it's repairable. I just had STick's 223,000 mile switch out last week to complete wiring repairs. Took the entire bottom of the unit apart. There are only three wires on there, red from battery and the red black back to the fuse block plus a blue orange which feeds the fan. When the key is ON, the red is connected to both the other wires. The connector is a spring loaded brass plate above the white plastic disc directly above the rivets to which the wires are soldered on the bottom of the white disc. Notches in the body of the switch provide ramps for the spring loaded balls swing left/right to make contact. Kind'a hard to describe but makes sense when ya have it all apart.

(Side note: I got into mine in Waterloo, IA a couple weeks ago when the bike quit dead. Problem turned out to be a factory defect cold solder joint on the bottom where the wires connect. 3 hours of disassembly/resolder/reassembly got us back on the road. Also got to meet some nice guys at the Salvation Army HQ there, and lunch with Rob Parker, whom I had not seen in a few years. :D)

Removal: getting to the switch to get it out is a real PITA. To do it right, the following must come off: panniers, seat, side covers, top shelter, air cleaner top and base. All because the connector for the switch is under and in front of the air cleaner base.

To remove the switch itself, two #40 Torx bolts must be removed. They are factory lok-tighted, and torx hole is shallow, easily stripped. AMHIK.

Once out, turn it over and see three small Phillips screw (#1 tip?) which holds a black plastic cap. Once removed, you'll see the solder points for the three wires, red to one side jointed to two rivet, black-red next to it, and blu-orange to another rivet a little closer to center. The white disc can be removed too with a little encouragement. Place a [-]tool[/-] towel on your work surface so ya don't loose any of the small parts. BTW, there's a second set of contacts which are unused in the ST application. Theoretically, the functions could be moved there but expect the wear would be the same.

In my case last Saturday the actual fix involved resoldering (again) the loose joint on the bottom, but while I had it out I took it completely apart and cleaned those moving parts. The fork lock was also not working so cleaned and lube it as well. All it takes is patience, elbow grease, and NOT loosing any of the brass plates, springs, or balls.

Reassembly is reverse. Since all the parts are "keyed", should be impossible to get it wrong.

BBTW, this is the second problem I've had. First was a few years ago (we were in this house so maybe 10 years.) Same problem as you are currently having. Did the remove, disassemble, clean and lube, reassemble. No real serious wear and that "fix" lasted about 70,000 miles. This time, the switch part was working okay but figured, what the heck. I expect it'll last another 50/60K with no further problem.

Another couple side notes: The key code is stamped on the barrel of the switch so if ya lose yur keys, a good locksmith can make more using that code. The torx screws can be a real PITA to get out so initial removal in a comfortable shop might save ya on the road. I was lucky to have access to more tools and help in Waterloo. I also "slotted" those torx screws with a Dremel this time so they will easier to remove should I ever have to again. Gonna do the same on lipSTick and STanley before the need arises.

But here's the real important stuff. The bottom of the switch can be disassembled without removal from the bike. Those three Phillips screws can be reached with the switch in place, and the cover, 'lectrical and contact parts pulled out. The harness is just long enough to let ya pass all those pieces up to clean air next to the right fork on top of the knee panel.

And, most important for on-the-road repair: you can cut the harness a few inches from the bottom of the switch and pull it up top, then strip the ends of the three wires and twist them together to get ya going again. All the lights come on, the bike starts as normal and away ya go. The blu-orange only provides power to the temp sensor so the fan won't run unless needed. At the next town, stop at NAPA and get some crimp connectors and a switch if ya want. This is what we did when my solder job failed the _second_ time in Colorado. Thanks to Uncle Larry and 970 Mike for sticking with me on that one. :D

Long winded I know, but real info in here for the High Mileage folks amongst us. Suspect all this is true for many Honda bikes and others as well, as the switches are usually pretty simple compared to what they put on our cars 'n trucks these days.

Should'a took pictures.
 
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jwumpus
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Those two #40 torx bolts are considerably more difficult to remove than I expected.

Sent from my VS880 using Tapatalk
 
Joined
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2000 ST1100 ABS TCS
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004
Those two #40 torx bolts are considerably more difficult to remove than I expected.

Sent from my VS880 using Tapatalk
Rob Parker sez they are intended to never be removed, as a security feature. At the same time, those three Phillips screws come out pretty easily, and a folded piece of chewing gum wrapper strategically placed in the bottom of the black plastic cover, then reinstalled, would connect those solder joints just like turning on the key on. Expect every experienced bike thief already knows that. :D

Rob also sez the bikes are engineered for "only" 200,000 miles, so STick is more than 10% past her service life. :D

On that note, her original speedo cable and the speedo head itself gave up on the way home too. Replaced the cable, disassembled and reassembled the speedo head (and added the missing 2000 miles too). All is good, for now.
 
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687
I have a question for those who have purchased the replacement contact part.

It looks like the replacement part includes both the white and black contact pieces, is that correct? In other words, all electrical contacts would be new upon replacement, not just the black piece that's attached to the end of the cable.

ignition switch.JPG
 
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004
Here's detail to go with dwalby's parts post. By hook or crook, I have a spare ignition switch, just came across it while searching thru my "STuff"; this is either from Gunnar's Silver One or The Hulk which he gave me several years ago.

Anyway, from left to right: three screws, bottom cover, zip tie which holds the harness to the body of the switch, harness and black piece with wires attached, white disc with contacts and spring loaded balls, body of the switch.

IMG_1954 (1280x960).jpg IMG_1955 (1280x960).jpg

In the first pic, the black disc and white disc mating surfaces are showing, in the next couple the bottom of the black disc and the top of the white disc are showing, then the "inside" of the body with the notches which mate with the balls. Note on the second pic, there are definite wear marks on the black disc rivets where the contacts on the white disc rub when the barrel is turned.

IMG_1956 (1280x960).jpg IMG_1957 (1280x960).jpg

The switch cannot be reassembled incorrecly as all pieces are "keyed". Unless there is serious damage, a little rebuild with some emory cloth and a little grease should get these parts working properly again. As to the lock barrel, I didn't disassemble but I have done on other switches and assume similar. It can be easily taken apart by prying the chrome cap. Careful, each tumbler in the lock is small, separate, and spring loaded. :D

Have to wonder if I brought on my own problems by not adding the tie wrap back the first time I had her switch apart (years ago); it provides strain relief. But a solder joint should never pull apart clean, just like a weld shouldn't.

I don't have a key for this switch but the key number is stamped on the barrel so a good key shop could make one or two.
 
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jwumpus
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Well I finally got the ignition switch off and completely disassembled. Looks very clean. Got the contacts nice and shiny with a bit of light sandpaper. Reassembled. Still the same behavior. The full on position does nothing but turning it ever so slight back to the left and I get power. I don't know. Maybe it's just worn out? It is 24 years old after all.
 
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I think I mentioned the futility of cleaning the thing in my first post, as your symptoms mirrored mine exactly. Now just buy the Honda part and do it right.
 
Joined
Feb 22, 2010
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Washington State, Skagit County
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'91 ST1100
Great tips and thanks for posting! Yesterday was stranded by an ignition switch problem and after some digging I ran across this posting of yours. I clipped the wires and twisted them together and it got me home after a long day on the bike. Thank You!
 
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Peoria, Illinois
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1995 ST1100
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I was able to refurbish mine on the bike without having to remove the connector. Each person's results can vary, hopefully the replacement piece comes in quick for you!
 
Joined
Sep 10, 2011
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West Michigan
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'98 ST1100
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8470
I just ordered a new ignition switch. I better get one now while they are still available. I'll replace it in the spring of 2018 as part of my PM schedule. I noticed used ignition switches on Ebay are not much cheaper than a new switch.

Also will clean and grease the swing arm bearings and replace the u-joint at that time too. Should have about 100K miles on the old girl by then ( if I'm still alive and if I haven't acquired a ST1300 or F6B by then ).

Seems like the switch should be easily replaced by removing the " fork top bridge " that it's mounted to.
 
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Seems like the switch should be easily replaced by removing the " fork top bridge " that it's mounted to.
Not necessary. Remove it from below. A few Torx screws to remove, disconnect the wiring plug and drop it down.
 

ST1100Y

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A few Torx screws to remove, disconnect the wiring plug and drop it down.
IIRC were there tamper-proof "snap-off bolts" installed, requiring to get drilled out... but could be year/area related variation...
 
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