Rewiring Headlight

Hey guys. So I've come to a point with my project that I'm stumped on. I have an 81 Seca 750. I've pulled off the old boxy headlight and also pulled out the stupid little warning system thingy that sits between the speedo and tack. I have a new headlight that I'm wanting to mount on and wire up, but now the problem I'm running into is that the original headlight was wired through that middle warning system thingy to get it's power. Since I've pulled that out and don't want it, I'm trying to figure out which wires that plugged into the warning system actually supply the power to the headlight so I can just bypass the warning system. The goal is to eventually strip the bike down to only the basic wire system needed and not have all the wired mess that mimics that of a car. ha ha Any help or ideas would be great. I've tried reading the wiring diagram in the Haynes manual and it just confuses me... lol

 

It's not quite that simple, the power has to go through the switch on the right controls & the high beam / flash on the left controls.

 

You will need to get a wiring diagram to figure it out. That's what I had to do when I stripped all the wiring on mine. It's a mess trying to trace the wires (you'll go cross-eyed) But you'll be happy when it's gone. What a relief (for me anyways) to have things simplified. If you do a search here, you should find a site that has the wiring diagram in two pages taht is clear and easy to read. I printed it out to take out in the shop for reference. It's a little easier to read than the one in my Clymer manual.

 

If you removed the computer system u may run into a few other complications not sure. As for this particular question the two wires u want a yellow and a green yellow being hi beem green being low are coming from the dimmer switch on the left handle controls into the main harness via a 4 pole connector (yes the haynes manual does make this part very confusing because I dont think its actually right, there are two mistakes involving your issue, too hard to explain right now) then once the two wires are into the main harness they travel to the computer throught another 6 pole connector inside the headlight bucket still yellow and green. use those two wires on a new headlight socket (should be available at auto zone or similar) pull a ground wire and you should have light!!

 

Actually I'm sorry looking at the print again there may be another mistake looks like green is high beem and yellow is low but I'm not possitive. You'll have to use trial and error. Use the stock socket as a reference maybe. they have stripes when the come from the computer but the main color is the same.

 

i'm using 2 relays one for high one for low, wired to the original high/low switch, using the stock power to that switch to trigger the relays and flip them over to the "main power" i have going from battery to relays then from relays to H4 headlight plug.

i hope that makes sense

it basically creates a totally separate headlight circuit, with better gauge wire and drastically reducing my chance of a melted harness from running my 110/120 watt headlight.

 

Thanks for your input guys. I was searching around some more and I believe I found exactly how to do it on my Seca. Looks like cturek had figured it out on his bike (let alone also adding a cool GPS system as well) So he was able to remove the ugly computer and cluster as well as the rectangular headlight and replace it with a nice round headlight.

Here is the link to his thread showing it just in case anybody else is having trouble with this on their bikes.

http://xjbikes.com/Forums/viewtopic/t=2 ... ments.html

He put a wiring diagram with the markings of where he put the jumpers and to what wires along with an explanation. Looks like it should be pretty easy with how he explained it. I'll post my results when I finish.

 

To ellaborate a bit more-
When I removed the computer monitor - speedometer - tachometer - square dashboard looking piece of ugliness (did I cover it all?) I first labeled all the wires to what they were for BEFORE I started cutting wires. I just used a tester and went thru all the wires to find out what they all do (it also helps to have a wiring diagram to get the colors right too)
Then after finding the suitable headlight, turn signals and replacement speedometer, I already had the wires I needed for the swap. The ones that were left over (about 8 wires I didn't need) I just sealed the ends with heat shrink and tucked them under the tank or inside the headlight (still labeled) so now if I do need any of them, I just start digging.

 

terceseht

If you have any problems after you start, just shout. We'll help out.

 

PainterD: Ha ha, yeah I think that pretty well covers it It's one ugly piece! And good idea on the labeling.

cturek: I definitely will. You still using that GPS on yours? Did you ever get a tach and/or odometer rigged up onto yours?

 

I have a gauge set from a 900, with the speedo,tach,gas. Does anyone know if the sending units are compatible between the 750 and 900 seca?

 

c21aakevin,
I don't know if they are compatable or not. I had to do alot of research to find the ohm rating on my (750 Seca) sending unit (can't remember right off hand now) And I missed having the fuel gauge when I got rid of the stock gauges. So after looking high and low for a suitible candidate, I found an automotive type gauge that works. Only problem is, it's backwards. Empty means full and full means empty, so I took off the face and re-labeled it so it reads correct.
Now I found one that reads backwards which is the same size, so I have to get one and swap them.
I can't seem to find any kind of sending unit that can be used in our tanks so far, so I guess we're stuck with the one from the factory. Then you need to find a suitable gauge that works. It's a pain. I'm still looking.

 

So where did you find your small round speedo and was it expensive? That's what I've been looking for but anywhere I look tends to be a lot more than I care to pay. And I went to the boneyard where I live to find a whole bunch of gauges for not too bad a price, but it's hard to tell if they will work. Many of them look rusted where the speedo cable connects.

 

Most metric speedometers will work on these bikes (cable driven) Just make sure if you find one in a bone yard, that the gauge doesn't have moisture in it (leaks) and the cable oulet is not stuck solid from rust. If you can find something to stick in the cable drive and spin it to see if the needle moves or not. That should get you on your way.

 

I paid 35.00 USD for a speedo from a suzuki dirtbike that had the same wheel diameter from a small one man repair shop not far from me. After looking on line and other sources, I jumped on this one.

 

The boneyard where I live said they'll charge appx. $20 or so for a gauge. Good price to me. Part of the reason I want to change mine so bad (aside from the ugly cluster itself) is because when I drive the bike, once I hit about 8 mph or higher my speedometer starts this squealing/screaming noise. And it gets louder the faster I go. Kinda hard to feel good about ridin your bike down the street while it's screaming at the neighborhood louder than an upset toddler. ha ha.

And what sucks is my cable outlet on my current one isn't rusted at all. And I have also taken it all apart and greased all the gears inside it and it still screams. Ugh. I just hope I don't run into that problem with a new one from the boneyard.

 

You must've missed a spot in there when you greased it. Should've sprayed some lighter oil in there instead. Hope the new one works out for you!!

 

Hey so it's been a while since my last update due to me moving this last weekend. (Just moved to St. George, UT. Man it's awesome being able to ride my bike and not deal with cold and snow anymore!!) Anyway, I know it's not what I really want, having the old boxy stock gauge cluster on my bike, but for the time being and for sake of saving money I did finally get my speedometer to stop screaming at me. PainterD was right, I did miss a spot and I did need to use a lighter oil in there. I found a thread on the forum that explained how to really clean the speedometer and I tried it using Break Free CLP (the cleaner I actually use to clean and lube my guns, ha ha) Worked like a charm! No more screaming from the speedo!

I also got my new round headlight rewired and mounted using the directions I mentioned a couple weeks ago. Worked great also and my headlight no longer flickers! Piece by piece the bike is slowly getting there I also added some new bullet turn signals and tossed the ugly huge rectangular ones. That helped a lot too. The remaining problem though with all of this is that I have a big wire mess completely visible on the front of my bike below my headlight. Just too much slack in the wire and no time yet to strip the wires down and get rid of a bunch of it. So that part looks kinda ghetto, but it'll be gone sooner or later. I'll post some pics of the progress when I have a chance. Thanks again for your help and input guys!