help please chasing down an electrical gremlin in my headlights

[vstrom.zrxdude]

My 06 had no low beams one day I noticed, searched here first, found info about starter switch issues, Cleaned contacts of starter switch with old can of radio shack contact cleaner lube I have, Fixed it never had problem again!

 

[ST Gui]

But you replaced the switch, and the behaviour did not change.

So either the new switch had the same fault - unlikely, but possible - or the fault is elsewhere. So where could that be
One possibility is the starter motor button. The right hand bulb power passes through the starter button, so that lights are turned off when starting the bike. You can use that to flash lights at night time... Another possibility is the circuit or connectors that feed the handlebar switch.

The starter button bug that John mentioned has bit several members here including me and an ST buddy.

They worked fine this morning on my way in to work... {shrug}

Intermittent function of the headlights is one of the symptoms of this issue. It's probably the quickest and easiest to diagnose and fix. Spray some plastic-safe contact cleaner into the right switch pod. I use WD-40 plastic safe electrical contact cleaner. It did the trick. There are others that work well too.

Work the starter button a few times (with Kill switch Off). While spritzing if you can. If your headlights functions normally (flashing on and off) you've bought some time and temporarily fixed the problem.

You should follow up by opening the pod and thoroughly clean it and apply a thin coat of grease to the switch functioning smoothly and impeding oxidation.

I'd recommend using a contact cleaner as above anytime you investigate electrical connections.

BUT— you replaced both left and right switches [control pods]. That would seem to exclude the starter button issue.

You can use that to flash lights at night time.

I do that all the time day and night –– as you alluded we're not blessed with a dedicated FTP switch.

 

[docw1]

Any other strange electrical activity? Does the high beam indicator in the dash stay on even when the high beams are not on

Could be a relay but older ST1300's are known to develop ground circuit problems. There is connector behind the left side fairing above the cylinder head. All of the ground wires for the front of the motorcycle pass through the green ground wire in this connector. It is often found overheated and melted causing all kinds of electrical havoc. There is another one behind the right-hand headlight- same thing but less common. I would first check the integrity of the ground paths.

Can someone show me pic of these ground points. I've looked and can't identify any common grounds. I've had some strange activity, and just noticed my right headlight sometimes goes out (I see the reflection on the car ahead of me at a stop light) and then comes on again.

 

[jfheath]

There is connector behind the left side fairing above the cylinder head. All of the ground wires for the front of the motorcycle pass through the green ground wire in this connector. It is often found overheated and melted causing all kinds of electrical havoc. There is another one behind the right-hand headlight- same thing but less common. I would first check the integrity of the ground paths.

That is always worth checking - but the main beam ground does not pass through this multi-pin connector behind the headlight according to the circuit diagram. I doubt that the terminals could cope with the current. However, the ground wires from the two relays do both go through this connector - if that is faulty the right hand bulbs would work, the left wouldn't. There is another multi-way connector on the circuit diagram with larger terminals that carries the main headlight ground wires. I don’t know where this is located - up front somewhere.
Probe the green wire under the headlight relay and check the continuity to the -ve terminal of the battery. That will tell you if you have a decent ground circuit for your headlight.

The starter button bug that John mentioned has bit several members here including me and an ST buddy.

I can see how it would catch people out. It was @John OoSTerhuis that first alerted me to this behaviour many years ago, so I chased it up - thinking that it would try to spin the starter motor as well - which would throw the gear into the engine and promptly get chucked out again. But it doesn't do that. The switch is a double switch - when the button is pressed it disconnects the power from the right hand headlight (dip/main) depending which is selected. That in turn prevents the left hand relay from being triggered. Then it connects power to the starter solenoid. That cuts out a massive 120 watts = 10 Amp current draw that the battery really needs to turn the starter motor.

The main earth point is in front of the rider's seat on the fram cross member. Easier to see if the tank is lifted. Early models had a recall - the wires were chafing on something (possibly the bottom seam of the petrol tank).

It is always worthwhile periodically unscrewing the bolt and cleaning up the copper ring terminals, and making sure that the frame is presenting bare metal to the terminal. A star washer doesn't go amiss either - they bite into the metal. Make sure the whole thing is greased once it is tightened up.

I belive that I once saw an earth point on the fairing nose stay - but its a vague recollection and I couldn't tell you where it is. The main battery earth point is on/near the starter motor.

 

[Andrew Shadow]

Can someone show me pic of these ground points. I've looked and can't identify any common grounds. I've had some strange activity, and just noticed my right headlight sometimes goes out (I see the reflection on the car ahead of me at a stop light) and then comes on again.

Dave ( @dduelin) had some good photos that were lost a few months ago. If he still has them maybe he will repost them.

Click the below link- there some photos there.
https://www.st-owners.com/forums/th...fter-key-is-switched-off.191709/#post-2601882

 

[ST Gui]

thinking that it would try to spin the starter motor as well

Speaking of vague recollections - as I recall my 750-K4's starter button would spin the starter with the STOP/RUN switch Off. It just wouldn't like a fire in the cylinders.

I'd read here that doesn't happen with the ST1300 so with great trepidation I tried it. It didn't. So it's my poor man's FTP button.

 

[Andrew Shadow]

I'd read here that doesn't happen with the ST1300 so with great trepidation I tried it. It didn't. So it's my poor man's FTP button.

I have used the starter button to flash my lights for years. Reading this jogged a distant memory however. I seem to recall pushing the starter button once and thinking that I heard the starter spin but I'm not sure about that as I had ear plugs on.

The starter motor might not be locked out when the transmission is in neutral, or if the clutch lever is pulled in. I'm not sure, and I haven't looked at the wiring diagram to check, or remembered to test it.

 

[ST Gui]

The starter motor might not be locked out when the transmission is in neutral, or if the clutch lever is pulled in. I'm not sure, and I haven't looked at the wiring diagram to check, or remembered to test it.

I haven't tested in those scenarios either and won't. If the engine is running I don't want the starter motor to attempt to engage under any circumstances. I only tried with the ST after reading more than one post that it wouldn't and seeing none contradicting it. Hearing inadvertent attempts over the years with different vehicles isn't pleasant.

 

[dduelin]

Can someone show me pic of these ground points. I've looked and can't identify any common grounds. I've had some strange activity, and just noticed my right headlight sometimes goes out (I see the reflection on the car ahead of me at a stop light) and then comes on again.

The crash removed earlier pictures. No pics, no problem. Remove the middle cowl on both sides. Above and to the right of the back side of the RH headlight is a yellow buss that collects several green (ground) wires and leads out with just one green. The buss isn't a connector that comes apart in two pieces. It appears solid but it can be pried apart. In the USA this single green wire goes into the wiring loom and comes out of the loom on the left side of the bike somewhere forward of the engine where it then goes into the large white 24 pin connector located above the front of the LH valve cover. You can't miss these two connectors. Many ST1300s with strange electrical problems have a compromise in the green wires going into or out of the yellow buss or the single green going into the white 24 pin connector. Temporarily you could fashion a jumper from the green side of the RH headlight connector that plugs onto the bulb and take it to a known good ground, like under one one of the two bolts securing the RH cylinder bank coil to the engine, and see if the intermittent headlight problem goes away.