Home Made EB headlight relay harness

So I finished the installation and things look good.

Picture of the harness placed in it's intended location and plugged into the headlight mini connectors on the left.
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Mini connectors on the right hand side of the bike. New harness plugs into these with no issues if you have maintained wire length.
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You can just see the 3 wires that were removed from the mini connector and capped with heat shrink. Connectors slathered with dielectric grease.
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Wiring harness, fuse holder relays and homemade bracket in place.
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Power and ground wires at battery.
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Battery voltage with engine idling was only 13.87 with accessories off and no fan. A bit lower than before.

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Voltage across Low Beam and Ground at the headlight was 13.21 volts vs 13.87 at battery. Not bad
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Voltage across high beam and ground connections at light equalled 13.04 vs 13.87. Still not bad.
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Voltage at the Mini Connectors (by the fork neck) between high beam and ground was 13.60 vs 13.87 at battery. Same value for low beam.
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So there was a big gain and a noticeable improvement in light output. The calculated voltage drop between battery and mini connectors was only 13.87 - 13.60 = .27 volts which is combined (positive and negative voltage drops together). From the headlight itself was a bit higher. High beam was 13.87 - 13.04 = .83 volts combined. Low beam was 13.87 - 13.21 = .66 combined. That short run from the headlights to the mini connectors could help a bit if the wire size was increased. Overall the voltage drop has been reduced from around 2.5 volts combined to between .7 and .8 volts. Big improvement.

All in all, I'm pleased and have some peace of mind especially with the ignition switch not seeing the load now although for a 2012, I thought the light load had been removed.
 
Nice job Gregger - very clean install

A couple of potential reasons for the voltage being slightly lower at the battery this time around;
1) If the engine was not at full operating temp the first time (vs this time), the idle speed might have been slightly higher and that few hundred rpm might be what is making the difference
or
2) The battery could be depleted slightly and is limiting the voltage until it comes up to full charge.

(you can test for which by just opening the throttle very slightly - if it comes back up to 14.2, it's the idle speed; if not, the battery is just pulling charging current and it will slowly come back up to 14.2 ultimately)

So you might pick up another 0.5V or so at the lamps once everything has stabilized and you are actually riding.
(but of course the loss won't improve from where it is now)

You did say there was a "big improvement in light output" - I think one of the most obviously noticeable things is not just the intensity, but how much whiter they are when you are looking at the lamps.
The next stage would be some better bulbs - that will be another significant incremental gain.

Re the losses in the final pigtails - in the quest or perfection, you could make up those in say 14ga - two of the male connectors (or just 6 new male terminals) and two new headlight H4 connectors.
(Some might just bypass the connectors altogether and go straight to new H4 connectors - however it is nice to have that 'break' point if you ever need to remove the headlights - rare occasion no doubt, but if/when you have to, you think "I wish I had a connector here!" :p )

But I think with the gains you already have, plus new bulbs you will be astounded at the improvement which is already quite credible, without worrying about that last few tenths.
 
I made mine. No cutting or crimping. Just plug right in. I do have h4 ends though for running the LED bulbs. They connect under the tank. I recommend putting factory ends on it for a complete plug and play harness for those still running standard h4 bulbs.



I added a fuse block to it and ring terminals once in the garage. Cut to fit!
 
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Just found the limit of pictures per post is 10 this one of the brass crimp on fittings I also solder them so they can not come off
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The brass fitting will only go one way so that they lock in now care fully study the relay package which will have the numbered pin and what goes on it remembering that we are using two relays, one for low beam which will use the red wires so apart from the power and earth in wires all the other red wires will go to one block and all the black to the other
EDIT I forgot to mention I fill the blocks with the Dielectric Grease as seen in the blue and white tube in some of the Pictures
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I using this photo series to show the best method of joining and finishing the other end of the power supply at the battery end
Note that I have the heat shrink slid up well away from the heat then twist the wires as neatly as possible
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Then sweat some solder into the twisted joint once cool slid the heat shrink down and apply some lite heat to it
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The end of the wire are the sweated with solder before crimping, I use a ratchet type crimper as it does a much better crimp than the cheaper types, also make sure you select the right size eyelet end pieces as to large a hole will result a poor connection
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The next post will identifies the wires to cut and join etc

Please feel free to contact me if you have any questions

the fitting of this relay harness carries on in post# 15

Fantastic writeup. I have a bone stock 2011 tour model and am having odd no start issues. During those events, the CEL comes on. I jiggle the switch and play with that loose clutch switch then it will start and run.
Right now, I am frustrated with this machine. The way they wired it does seem weird, wiring start through headlight. Would your wiring modification address my problem?
 
... The way they wired it does seem weird, wiring start through headlight.

The Start is NOT wired "through the headlight" - the way it works is that current is directed to EITHER the Headlight OR the Starter Solenoid - it has been that way on ALL Triumphs for at least 25 years. It isa actually a very clever scheme to turn off the headlights during starting to allow the starter and ignition system not to be dragged down further by that headlight current.

Would your wiring modification address my problem?

Almost certainly not.
It sounds like you have a bad connection somewhere in your starting circuit - possibly even the key-switch circuit itself. Although key-switch failures are rare on the Touring model, those I have seen have not been in the switch itself (as per the classics) but at the connector where one of the terminals is burned. So perhaps start by inspecting that. Or you may have a clutch switch (or its harness) issue.

It would be good if you could further define "not starting" - do you mean not cranking (starter won't run) or cranking but not firing?
Does your headlight come on when you turn on the ignition key? (when you have the problem)
Do you have idiot lights on your instrument panel? (Neutral, oil light, LCD display)

If headlight and all dash indications are normal, the starter simply won't run then most likely your culprit is either the clutch switch or the starter relay.
Also be sure to check that smaller ground wire cable that comes off the negative terminal - the connector in-line to there is a known failure point.
 
The Start is NOT wired "through the headlight" -
.

Thanks for replying.

What's happening is that I will do a normal shutdown and upon return, the CEL comes on when the key is turned and power does not get to the starter. Yes, my clutch switch is loose from whatever is supposed to hold it into the clutch handle base. I fiddle with that clutch switch and turn the ignition key a few on off cycles and then when turning the key again, the CEL will go out and the starter cranks it up. Bike runs fine once started. I guess I need to dive into that ignition and clutch switch but the manual is very weak on the clutch switch, little depiction, and Triumph has failed to get back with me.
 
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The switch is very simple; it is a normally closed switch (closed when the lever is pulled) and held 'open' when lever is in normal resting position

It should certainly not be 'loose' in the perch - has one of the clips broken off or ???

Quick question - do you have OEM or after-market levers?
If the latter, that could certainly be an issue - very common - when the lever is pulled, the pin on the clutch switch does not extend far enough to enable the switch to close.
 
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post: 590722, member: 3206"]

Quick question - do you have OEM or after-market levers?
.[/QUOTE]


My levers are the OEM ones. That clutch switch just hangs loose. The manual is kind of weak in depicting how the thing is held in there. I have been told that this may be the source of the fuel indication system problem as well. The stem inside that switch is plastic and has come completely out before. I just stick it back in there and wiggle it around. Can't figure out how it is held together.
Simply can not get any support from Triumph on this. Here is all I could find in the manual.
 
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