Strange Electrical Readings from '96 ST1100

[Tackleberry]

OK electrical and knowledgable ST1100 people.  I have a little problem with the ST that arose in the last two weeks, and I need it sorted so I don't dissapoint a little boy by breaking a promise.  Normally this wouldn't be a rush job as I would park the bike up to find the error, but I promised my 10yo son that I would take him on the next FarRide to Eungella, which I also happen to be the organiser so I need help, instead of searching for it myself like I would normally do. 

Earlier this year I got peeved at the different wiring throughout the bike, and thought I would get the fairing frame repaired, and fix up wiring through fuse holders etc to clean things up.  Bike got stripped to: 

         

This is not the first wiring job I have done so I am pretty confident when it comes to wiring, and I have had calcs done of all the farles I run to ensure I have sufficient amps available to charge my battery also, whilst having some spare just in case.  Which my current set-up complies with.  The alarm that has been installed also cuts out the starter circuit so it can't be started by cutting alarm wires, because fues has been removed. 

OK the last service was done by a mate and I (he has more knowledge than most mechanics when it comes to bikes) and we had to push start the bike when I went to leave.  We thought this was becaus ethe bike was staretd a few times, and had been sitting for a while, so no biggie.  On the way home the bike died.  No electrics, no start nothing.  Changed battery with another bike, and flattened it in 15km.  Checks done and found 50 amp fusible link gone.  I don't mean burnt out, I mean GONE.  Never had cause to remove it, so mystery number one.  Replaced and no further issues, so I thought. 

About three weeks ago, nearly two months after service, noticed that the dash lights, and tail lights aren't working.  Now there are the only ones i HAVEN'T stuffed with in my rewiring.  No dramas I think I will change to fuse.  Nah the fuse is still good, and when you wiggle it the ights come on.  When they are out, Speedo and Tacho still work, but Fuel gauge and temp gauge don't.  Anyway change fuses over as a matter of course to see if this removes the problem, which it seems to do.  Rode around for three days with no issues.  Also noticed that voltage gauge was showing about 13.2v, which is OK if you take the half a volt drop from an ignition sourced wiring point.  Checked the battery across the terminals and showing 14, so happy with the reading on the gauge. 

Advance to ride south for Rememberance which I have just completed.  Found that lights were cutting in and out, until IU gets to Brisbane and loses them when leaving to head towards Sydney.  At mates place in Sydney, and previous owner of a '94 ST1100, and member of the Email list, we again look around and find that installing the fuse for the igition, which is controlled by the alarm, returns the lights.  Also noticed when riding that it nows pushes the voltage up to around 14.1, which I was a little concerned about with a half voltage drop across the circuit as normal.  Also noticed later that night coming back from a ride that the lights come and go as they please.  If you take the bike of centre stand after refuelling they come back on, but go off the next bump in the road you hit. 

24hrs later and now no response from the lights at all.  Still have brake lights, and blinkers, but no tail light, or dash lights, fuel guage or temp gauge.  Between Dubbo and Wandoan, yeah I know only a short day for a FarRider (800km), but it was one of them days.  Noticed that the Volt gauge was spiking to up around 15.7 at times and averaging around the 15.2 marker.  Thought about what heppened when I installed the fuse for the ignitiion, so when I got to where I was staying I pulled the fuse to see if it would counter act the high readings, to try and save some of the electrics from high the high voltage.  (unfortunately didn't pack my voltmeter this time)  Still have high beam light indicator, indicators, ABS indicator,

Anyway I heads off from Wandoan towards taroom when I noticed the ABS light flash several times and then stay on.  Now there hadn't been any extra signs of problems, and volt showing as around 14, not at 15 as day before.  Have had this before on other bikes, and thought I would stop, turn the bike off, and back on again.  When key turns off, everything dies, NO electricity at all.  Clock dead, no lights, no response from starter button, nadda, zip, nothing.  15 mins laterfully packed bike back together and running with fuse installed into the ignition again, and now the alarm wires removed, and only providing power to the multiple extras that are tapped into it, eg GPS, cigarette plug etc. 

Ride into the night and start noticing that the HID's installed start flickering on low beam.  Voltage showing around 15.3, but drop to 14 when High beam, and HID spotlights are turned on.  Flickering varies through the ride to really noticable at times, to thinking that was a flicker.  Happened once or twice on high beam, but very noticable on low beam several times. 

Anyway the typical story of Mr Honda's ST1100 was that she finally stopped on me..... when I turned the key of in the carport she is normally parked in.  Picked her because of the great experience we had with them at work, and the typical response you get from them is to keep going no matter what you do to them. 

So my primary concerns are the usual suspects of: 

1. reg/rectifier, which in this model is attached to the Alternator at the bottom of the engine, just above the side stand which requires rear wheel & swing arm taken out and gymnastics degree to remove; 
2. One of Mr Honda's fuses playing games; 
3. I stuffed up somewhere in re-wiring efforts; 
4. Alarm has gone all 'Skynet' on me; 
5. Or combination of above. 

Let me hear you thoughts brothers and sisters of Honda devotion to help me keep a promise to an anxious 10yo boy wanting to get his FarRider Number.  Oh yeah have to leave for Eungella on the 30th September, and turn up to work for a few days according to the roster clerk. 

[Brock]

Its hard to give solid advice, but here goes.

The fault(s) sound like a loose termination some where. Easiest way to start is disconnect the farkles, including power feed. If you can, disconnect the alarm.

Now ensure that all terminations are solid (not sure what termination system you used). You should be back to standard fit out by now. Does the system work.

If yes, then good. You can now start to plan to return your farkles one by one. Plan to use one power feed to a central pick up point if you can. Maybe you can start with the Alarm system.

Electrics can be puzzling, so do the simplest thing first, and do things one at a time. I have been doing electrics (aero stuff) for 40 yrs, and i still get confused at times.

Alternative method, is to slowly disconnect the farkles one by one and test for correct operation each time.

Its possible that you have introduced a short/high current drain some where, and this may affect your regulator (hopefully not). It may even be a crushed wire.

P.S. what was the last farkle fitted before the problem raised its head, perhaps start backward from there.

[Malcolm6112]

I would agree with Brock. It doesn't take much to pinch a wire and have it earth somewhere.

[saaz]

I don't have experince with the 28amp models, but it sounds a bit like all the basic connections need to be checked.  One of the real basic tricks with the 28amp models is checking that all the connections from the reg/rectifier and starter relay are ok.  Sometimes the connections play up, and it is best to solder them together.  Having an alram in the circuit worries me as it depends on how it is connected.  If the clock dies that is a classic case of the connection going into the starter relay (left of the battery) being burned and creating resistance, then dying.  Cleaning it up and tightening up the conections can work.

[Tackleberry]

Fellas thanks for the replies.  Started playing again this afternoon and found that the connector to the fuse is connecting sometimes, but not others, and the charging seems to be back at normal levels. 

The '96 is the first of the 40 amp alternators and the regulator/rectifier is built into the alternator unit under the motor, which is why I am having trouble checking the connections around the unit.  Around $800 replacement costs. 

When I first hit the starter button this afternoon, everything died again, and then after moving the bike off centre stand and working it around the garage it started again with no dramas. 

The problem keeps displaying like a loose connector somewhere, just a matter of finding it. 

Alarm is connected to the positive and negative of the starter fuse, locator near the battery.  The Alarm also has a seperate power feed to activate the indicators, voice module & siren separately.  It also has the capability of starting the bike if I wanted to connect that, which I didn't.  The final connections to the starter circuit was done by the electronics guru's at work that install these types of things daily as part of their occupation.  They did all the checks and set up to ensure it was correctly installed. 

[saaz]

There are a couple of earth connections to the frame and engine to check.  The connector into the top of the starter relay can overheat and lead to no power (left side, to the left of the battery and fusible link)  The connector may have overheated, or could a previous owner attempted the know bypass fix, which means splicing in another wire?).  Worth checking all the connections up to the ignition switch, as all the power (other than for starting) goes up through there and back down to the fuse box through that connector that overheats (and that is why it overheats!).

[Tackleberry]

Thanks Saaz.  I will check this when i get five.  Sounds like a good match to my problems.