Left headlight fuse internittent blows

acadian

Hi,

As I said in my introductory thread, I found this site while doing research for a problem that I have with my ST1300.

Out on a ride, noticed dashboard Hi-beam light out ? stopped to check headlights ? nothing on left side ? left is while sitting on bike.

Got home ? checked fuse ? blown ? replaced ? everything back to normal.

Next day while getting ready for ride ? rode bike out of shed ? problem back ? checked fuse ? blown again ? replaced ? blew right away.

Time for some reading and research ? I know nothing about electrical circuits ? so I may be missing something a knowledgeable person would catch.

Stripped down the bike on the left side ? lots of crud and dried out dead insects.


I do a lot of "things" ? only to burn out about half a dozen fuses.

Not using a systematic approach, there are things I can confirm after the fact and unfortunately, things that I am not sure about.

Here's where things stand right now ? checked battery for voltage and current leak ? seems OK ? checked headlight relays, again seems OK ? checked bulb connector, fuse box, relay connectors, and what wiring I can see ? nothing funny.

The only thing I have noticed ? I blew a few fuses by pressing on one side of the fuse while it was in the fuse box and also by wiggling the fuse box ? all the while with the fuse box in its normal position. I think I also managed to blow out a fuse in this manner with the contact "OFF", but I am not sure.

There are two "black/red" wires soldered together in a "double" connector to the fuse box and leading separately to each headlight relay ? I removed that connector from the fuse box ? nothing out of the ordinary ? looks "new". All the wires and connectors seem in "new" condition.

After blowing a few fuses, put one in and everything back to normal.

I have picked up a lot of useful info on this site ? checked them out as best as I could ? nothing pans out.

Back to the bike after a day off ? turn ignition switch ? everything ok ? start engine ? still ok.

Turned engine off ? pull and wiggle wire bundles here and there ? blew a fuse ? zero in on where wires meet in a "Y" under seat position ? pull and wiggle ? again blow a fuse ? eureka! ? found my problem I tell the wife.

Take off all the tape ? pull out the two relays and the two fuse boxes from their normal position ? pull back on wire bundles to move them out of their normal contact position with frame metal parts ? check as best as I could, can't see a darn thing ? wire insulation seems in perfect order ? no sign of sparking on metal parts.

The only thing I notice ? the two black/red wires in the wire bundle going/coming from the fuse box leave this wire bundle for the wire bundle going to the relays ? at this point these wires are not covered by tape ? and are in a tight "u-turn as they change direction. I opened up the "u-turn" so as to remove the "pinch" in the wires. No damage to the wire insulation as far as I can see.

Put a fuse in ? turn ignition on ? everything ok ? do all kind of pulling, twisting and wiggling ? I can't blow a fuse ? start engine ? turn Hi-beam on/off ? nothing ? push wire bundles back in position ? pull, press, twist, wiggle ? can't blow fuse ? move to front of bike ? pull, press, twist and wiggle wire bundles ? can't blow fuse.

Right now everything is in working order but I have not taken the bike out for a ride yet. I know the problem is still there and that bugs me ? I would like to find something before I put the plastic back in place.

If anybody out there can provide advice/counselling ? feel free ? I am getting desperate ? and boy do I hate electrical problems!

Ken
 
Check the articles section for Anna'sDad schematic of the headlight wiring.
LINK


If pulling an twisting popped a fuse you have something rubbing on something you just have tripped over it yet.
Poking and prodding etc moved the exposed wire so it's not hitting anything for now.
 
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I don't know the year of yours Ken, but there is a wear point at the left side of the steering pivot head (mostly on 2003's IIRC) where the wire loom is trapped between the clutch hydraulic hard line and the steering head. You may have temporarily moved some worn insulation away from the short-to-ground.
 
BakerBoy said:
I don't know the year of yours Ken, but there is a wear point at the left side of the steering pivot head (mostly on 2003's IIRC) where the wire loom is trapped between the clutch hydraulic hard line and the steering head. You may have temporarily moved some worn insulation away from the short-to-ground.
Click to expand...
Happens to more years than the 03, if you do a search you'll find pictures etc. but bakerboy has it right, just look on the left side of the steering head, there is a plastic thorn that sticks out there, the wire loom rubs on that until it bares wires then once in a while you will short out to the frame, looked for that gremlin for days before I found it. Here's one article on it.

https://www.st-owners.com/forums/sh...0-Intermittent-blown-fuses-caused-by-wire-rub
 
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In reply to the three posts above ...

Mine is a 2008 ST1300 ...

I have located the two different rub points at the front of the bike ... and inspected the wiring bundle containing the wiring for the left headlight ... everything seems in very good shape ... I did a test of moving the wire bundle up and down and twisting it around trying to blow the fuse ... nothing happens ... as a matter of fact, since removing all the electrical tape from the wire bundles around the fuse boxes, relays and the "Y" above the gas tank, (ie underneath the seat), I can't get the fuse to blow no matter what I do! The only thing that I have done is to remove the kink in the two black/red wires between the fuse box and the relays.

If there is an exposed wire somewhere, I'm afraid my "fooling" around has moved the faulty wiring such that it is now "protected" ... as some of you have stated ... a problem looming in the dark to hit me in the most inappropriate moment I'm afraid!

Ken
 
Eur?ka!!! ? I found it! The famous bare wire touching metal!

Since this was something just waiting to happen, based on how the wiring was laid out ? I think it could also happen to others. Knowing it beforehand, it is very easy to fix.

Remove the seat ? from the battery at the right hand side of the bike, the wires cross over to the left hand side of the bike ? near the grab handle. Halfway in between, the main wire bundle splits into two smaller bundles going down the left side of the bike.

The rearward bundle splits again ? one bundle going to the fuse boxes, another going to the relays.

Two black/red wires jump from one bundle to the next ... these are the wires going from the fuse box to both relays ? they are not covered up by tape or plastic sheath ? and they are bended into a sharp u-turn. Close by, there is a bolt/washer attachment. The black/red wire to the hi-beam relay must have been rubbing against something in that area. There was a small exposed area close to the bend in the wire.

Before closing up the bike, I will put tape in every area susceptible to wire rub ? as pointed out on this site and others on the internet.

Thanks again for the tips! They really pointed me in the right direction.

Ken
 
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