1982 XJ750 SECA Head lamp failure.

I got my bike about 2 weeks ago. Everything seems fine but I've been having trouble with the electrical system.

It had charging issues when I first picked it up, I've been having trouble with the battery dying/not charging, and leaving me stranded. I seem to have remedied the problem by replacing the battery, but I'm still suspicious that the stator or r/r aren't running 100%



Anyway, here's what's giving me trouble now. The headlight just doesn't work, at all.

A couple days ago my headlight went out. I killed the engine, checked the fuses (they were fine) and jiggled the wires, turned the bike back on, and the light worked fine. I went to Home Depot and bought a multimeter a couple hours ago and did a little testing. I made 2 tests and here's the results I got.

1. I removed the headlight fuse. I stuck the multimeter's red lead in the fuse terminal, off the brown wire, then I stuck the black lead on the bikes frame. I got a reading of roughly 12-13 volts.

2. I removed the headlight and tested the headlights wire harness. I stuck the meter's back lead in the terminal that connects the black wire. I then used the red lead to test the other two terminals. with the motor idling I got 12 volts from one terminal and 4 volts from the other. I then switched on the high beams, with the brights switched on the meter read 12 volts on both terminals.


Now I need some help, I have the bike, a multimeter and basic tools all right here, so if anybody has suggestions for me, I'm all ears. With this being the beginning of summer, all the shops are running a 2 week backlog, so I'd really like to try and take care of this myself.

Also, if there is a quick fix or bypass anybody knows about that could get my lamp running temporarily, that would be a big help too.

Thanks guys! I'll check this thread often, and keep y'all updated on my progress.

The next day I was riding home from the bar and my headlight just went out. Got home, poked around a little (not sure what I did, if anything) but the light came on when I switched the bike back on.

Now it's not working at all.

I checked the fuse, it was good. Tried replacing the headlight, no bueno. spent maybe a half hour poking and tugging at the wires, still no luck. [align=left]

 

Loose connection somewhere is what it sounds like. If you still have the stock fusebox (with glass fuses), that's probably the culprit,as the metal "pinch" terminals that hold the fuses get weak over time, and don't apply sufficient pressure to really grab the fuse. Next time the headlight is NOT working, use a jumper wire to jump across the headlight circuit fuse and see if the headlight comes on........if it does, you know where the problem is. Time for a fusebox upgrade!

 

not headlight related but you can check your altenator by measuring the voltage on your battery before cranking, during cranking and during 'idle' (actually about 2,000rpm)...

here are some pics...







you have to rev the engine up a bit past idle because the charging system doesnt start charging until it gets to a certain engine speed. im not sure of what that speed is but someone here will help us out i know...

 

Don't know what's wrong with your system, but I can tell you how it's hooked up, which may help:

1. The headlight is powered through a relay that latches "on" once the bike is started and the alternator is generating a bit of power. If the alternator's not charging, the headlight won't come on.

2. On the 750 SECA's, the headlight power also runs through the computer. This is so the computer can verify that the headlight is drawing current (not burned out). If your computer is not warning you about the headlight, then the computer doesn't expect the headlight to be on, so it would probably be a relay/charging problem. If it is warning you about the headlight, then it could be a bad connection along the way or a problem within the computer module itself.

 

Try to measure your voltages using the black wire as your ground reference. High beam is the Yellow/Green wire and the Low beam is the Green wire. If you are seeing the correct voltages in the right places at the right time, the bulb must be suspect. If you don't see the correct voltages, the digital instrument cluster is your next suspect. Make sure that the correct voltages are going into it. Trace the lines from the headlight dimmer switch (Yellow, Green and Black) and check the voltages there. If nothing at the switch, check the headlight relay. If no voltage is seen out of the relay and you have voltage on the fuse, the relay is bad. Pull it open and clean it out before condemning it (they can be opened and they aren't cheap).

 

Thanks for the reply Lt. Dave

I just went out and checked it.

Before I started the bike, the battery was right at 12.4 volts

I started it with the choke on 1/3 of the way. (the engine was cold and my bike doesn't like to idle) that kept the rpms up a little too. My tach doesn't work so I'm not exactly sure how fast it was running. It fluctuated for about maybe 20 seconds when I first started then settled around 14.3 volts.

 

Wild, what is your general location? If you are local, I'd be happy to offer my assistance with your problem. I know that quite a few of our members help out others so you might be next!

 

SQLguy: I wanted to take a look at the relay, but I left my socket set at the bike store where I work. I will tell you 2 things though.

When I start the bike (or just switch it on) I do not get a HEAD warning, however, then I remove the bulb, I do get a HEAD warning.

Robert: I'll try what you said tomorrow, I'll have plenty of tools at my disposal at work. Right now all I have is a multimeter and a screw driver.

I did test the leads coming from the headlight with the bulb removed the way you said. When the bike is running I get about 4 volts from one wire and 12 volts from the other (that's with high beams off) I don't know where the dimmer switch is.

 

Thanks Robert. Unfortunately I'm in Pittsburgh PA. I'm actually planning to move to CA pretty soon, but for now there's about 2500 miles between us.

 

my maxim has a fuse in the headlight bucket, not sure about the seca
what side of the city you on?

 

Hi Polock, good to meet a local.

I live right around Highland Park/Shadyside right in the city.

It didn't say anything about fuses in the headlight bucket in the Haynes manual, and I didn't see any in that nightmare of wires.

 

The Seca has a 5 amp fuse in the bucket for the instrument lights. I'm not 100% it has anything to do with the headlight (the schematic runs it right into the computer so where it goes from there is anyone's guess). Do you have a maintenance manual?

 

You guys are doing great, keep the advice coming.


I am up early this morning wrenching on the bike again.


I just have to know one quick thing, because this is just driving me insane.


I pull the bulb out, fire the bike up, and test the leads in the socket where the bulb goes. If I have the high beams switched on, I get a good strong 14 volts out of both of them. THE LEADS ARE GIVING ME POWER.

I tested to bulb by connecting it to an alternative power source. The bulb works too.

So the bulb works, and the socket gives power.

The how come when I plug the bulb into the socket it doesn't effing work?

Please excuse my frustration, but this is just driving me crazy.

 

How are you checking power in the connector? In other words are you getting our ground from the connector or the frame? Could be the connector's ground is flaky since the bulb is good and you have power.

 

I'm getting ground from the connector

 

Ok, you know what...

I just want to do a temporary fix to make it work.

Let's say I bypassed the whole damn thing... I run the positive right off the fuse box, and I ground the neg to the frame, and hook those directly into the headlight


I know I won't have high beams, but at least it will get me by for now.


is there any danger in this?

 

Dang I was hoping that might have been it. Makes no sense if you have power and the bulb is good.

 

bad socket maybe wiggle jiggle the bulb