"Dimmer" Blue Hi-Beam indicator on ST1300

Afternoon all,

Looking for tips to correct a minor annoyance before it becomes a real problem. Riding around this weekend in wet weather, the dimmer indicator on my 2005 ST1300A came on and stayed on for a while. No other signs of any malfunction - the dimmer switch operated the Hi-Lo as usual, but with no change to the indicator light status (e.g. it stayed on regardless of the actual beam selection). No change from stopping and re-starting the bike. It did return to normal after my trusty STeed had time to dry out, but came back on with more wet weather riding. Now it is dry again, and operating normally.

So obviously, water/humidity is getting in somewhere and causing power to be applied to the indicator light (I think the light was not as bright blue as it is when operating normally, but that is pretty subjective). As I have ridden in all kinds of weather before and this has not been a problem, I suspect something has either come loose or cracked with age, letting moisture in, a situation that should be corrected before it degenerates into something more serious. But where to look? Any tips would be greatly appreciated.

PS: It should be noted that I have modified my lights to fanless LEDs, which required a modification to the boots so that the connectors would fit properly. Pictures attached, in case that may be where the issue is.

Just the indicator or were the light actually on high? It's pretty common for the switch pods on both handlebars to get gummed up with dirt... cleaning those out may fix the issue.

When my '06 was behaving in a similar manner, I traced the fault to a bad ground conductor at the left-hand headlamp. The conductor was fried, probably started as a dirty connection at the bulb connector, that over time worsened increasing the resistance of the connection...

Here's a link to a sketch that I made to demonstrate to myself just how a faulty ground connection could cause the high beam indicator to remain lit.

Most likely not the ground wire since you have LED lights. The led power converter should not back feed power to the indicator as would the halogen bulb. You should trace the left hand high beam wire (blue/black) back to the relay that is under your seat on the left side. I would suspect the left high beam relay or the relay socket. look for contamination.....

The other possibility would be the leds. Just swap led connections. The LED wires should be long enough. The HI indicator only runs off the left high beam wire....

see post #22 here

https://www.st-owners.com/forums/showthread.php?62641-ST1300-Headlight-Wiring-Diagram&p=706872&viewfull=1#post706872

spiderman302 said:

I would suspect the left high beam relay

Click to expand...

This is exactly the cause of a problem my ST buddy had. His symptoms:

If he turn on his high beams the lights worked properly.
When switching back to low beams the indicator stayed on as did the left high beam.
To get both low beams back he had to switch the ignition Off then On and all was well. At least until he switched to high beams again.

A new relay put everything right.

That has happened to me, twice.

The first time, the indicator light (and high beams themselves) stayed on after I switched from high back to low. It would also come on at start-up, or while I was riding and not hitting the high/low switch. Traced it to a badly-corroded (nearly failed) ground wire to one or the other bulbs, right at the connector. Clipped the connector, cleaned up the wire, replaced connector with new, no more issue. Not obviously related to moisture in the air.

Second time was just this past Saturday. Again a beautiful dry day, after 30+ days of no rain, so not a moisture-related problem I think. High beam(s?) reluctant to shut off after toggling the switch, though they do eventually dim. (Not sure whether both remained on or just one, since I was riding.)

Have not had time / opportunity to investigate further, but I have also noticed a faint whiff of hot electrical wires from time to time so I suspect another high-impedance spot somewhere.

I plan to check, in order:
* condition of wiring at the connectors
* condition of the switch
* only after those have both proven not to be the problem will I consider going after the relay.

Then again, I run 60/55 Silverstars, rather than LEDs, so spiderman302 may be on to something with his diagnosis.

Good luck in the hunt-

Ground circuit corrosion problems cause all kinds of weird electrical symptoms. Current will run to ground somehow even back through seemingly unrelated circuits. I had to repair my cooling fans ground when I had an errant high beam indicator like the OP.

Thanks guys,

That gives me good indication of what to look for. Just to be clear, when this problem manifested, the dimmer switch operated correctly. e.g. even when the indicator was permanently lit, I could switch my Hi beams on and off normally. This is going to be fun to look for, as it is an intermittent problem. I will update this thread if or when I find something.