Electrical headache, anyone?

[Materi]

I keep blowing headlight fuses. I've traced the entire circuit and can't find any obvious defects. Here's the wierd part.... the light still works on high and low, but appears dim..with the fuse removed! The head lamp warning in the cluster will occasionally illuminate, but when I honk the horn, the head light gets bright, and the warning lamp goes out. The warning will stay off until I shut her down and re-light, when it comes back on. I am hip to the reserve lighting deal, but I don't think it is running on that. The battery is charging good as far as I know after 250 or so miles. I suspect maybe a crappy ground in the left switch cluster, and I also think PO may have tampered with reserve lighting device, as there are wires and connections there that appear out of place. If I leave the fuse out, everything seems to be fine. Any ideas? Thanks in advance.

Keith

[TopCatGr58]

Hey Materi,

If you're blowing fuses, then you've got a short to ground causing too much current (Amps)to be drawn thru the headlight circuit frying the fuse. DON'T RUN IT WITHOUT THE FUSE, otherwise you could cause a fire where it's grounding. You need to get an ohmeter and trace that circuit. The nest of wires in the headlight bucket is a good place to start, as well as where they enter/leave it, rubbing can occur anywhere against the frame.

Like you said, if the P.O. messed with the reserve unit and it's connections, they may have inadvertently connected a hot wire to a ground wire!? Your best bet may be to bypass it!?

Yes, check the switches in the handlebars too, those solder joints have been known to corrode or come loose and could touching other conections next to it, or the handlbars=ground!?
HTH, Good Luck. T.C.

[TopCatGr58]

Hey there Materi,

Followup after looking at your pictures! I see you have a set of what look like blue halogen aux lights on a bracket on the frame!? If the P.O. wired them with/thru the same circuit as the Headlight, that could also be causing your excess amp draw and fuse blowing?? They really should be on a separate circuit IF they are not!?

I have mine connected from the Aux. fuse link at the fuse block!
T.C.

[Shuriken]

I had a Yamaha XS650 that did that. I tried everything. Could not find the problem. Sold the bike that way with it in the disclaimer.

Ben

[Materi]

Thanks for your input fellahs,

TopCat, I am worried about that grounding problem, and have no desire to eject due to an in-flight fire may-day type situation. I don't know, man..I'm still looking to find it. My aux. (mood lights, as my brother-in-law likes to call them) lights, however are also running from the acces. circuit, so that's not it, I don't think.

ae7f, bummer you had to sell the 650, and though I can certainly relate to the old frustrate-o-meter being pegged out, I'm not selling mine.

Thanks again,

[Shuriken]

It was time to sell it anyway - I purchased the XS11.

I loved my XS650. It was bulletproof reliable, simple, and fun. When I sold it, it looked like this. But having the XS11 and then not being able to solve the headlight problem forced me to get rid of it. I broke even - I bought it for $400, sold it for $850.

I tried circuit-breaker (resetting) fuses, compass tricks, everything to try and figure out why it was frying my headlights. Ran out of time as I began shifting attention to the XS11 (carb hell, etc.).

I had a fuse-blowing problem on my XS11 when I got it. I spent about 2 weeks straight checking everything. Finally, at about midnight the last time, I had a thought to unplug the connectors to the horns. Problem solved. Only took me 2 weeks straight.

I'm not above shredding the wiring harnesses apart and looking for bad wires and/or rewiring all together.

When you find the problem I would really like to know what it was.

Ben

[Materi]

I know a guy with an old XS650 sitting in his back-yard in general neglect. He won't sell it though, because "someday" he's going to restore it. I don't really mind shredding the harness either, though I'm trying to avoid that at this time as I don't want to miss out on all of this great riding weather, which as you may imagine is pretty rare in Wyoming. About every other night, I head to the garage to "tinker". I'll keep you posted.

Thanks again,

[TopCatGr58]

Color Wiring Diagram

Hey there Materi,

Here's that Color Wiring Diagram for the 79SF, it's at 200 DPI, ~ 8"x10" portrait, but you'll need to turn it sideways to read it. You can/should be able to print it at full page size, may need to use your graphic program to ensure that it gets fitted onto 1 page!
Color Wiring Diagram for 79SF
T.C.

[Geezer]

Re: Color Wiring Diagram

Originally posted by TopCatGr58
Hey there Materi,

Here's that Color Wiring Diagram for the 79SF, it's at 200 DPI, ~ 8"x10" portrait, but you'll need to turn it sideways to read it. You can/should be able to print it at full page size, may need to use your graphic program to ensure that it gets fitted onto 1 page!
Color Wiring Diagram for 79SF
T.C.

Do you have one of those for a 79 or 80 standard?

Geezer

[Shuriken]

Thanks for the .JPG.

Ben

[Materi]

Many thanks for the wiring diagram. We have currently deduced that the headlight relay was also pretty hot, y'all think this could be causing any trouble??

Thanks again,

Materi

[thumperjsa]

The headlight relay could have a lot to do with it. Right now, thanx to the PO, my bike has no relay. The blue/black and red/yellow is jumped. Looks like the connector is a little melted and they removed the relay.

It is interesting how the relay is setup based on the fact that it does have two power sources from the generator coming into it. One is through the fuse (red/yellow) and one is strait from the generator (yellow). I don't for sure know the function of this relay but apparently my bike has had a jumper wire for a relay for some time.

[Shuriken]

Where is the headlight relay located? I need to check mine...

Ben

[thumperjsa]

It should be under the gas tank. At least that is where mine is supposed to be.

[randy]

Thumper,

To answer your question about the relay, it is a simple latching relay. It uses the signal from the alternator so it knows whether or not the engine is running. When the alternator signal is good, the relay pulls in and applies battery voltage to the headlight. The same lead for the headlight also (internal in the relay) backfeeds the positive side of the reay coil to provide the latch, which keeps the relay energized. That's why when the engine stalls the headlight stays lit.

I'm intigued by the number of forum members who are so willing to cut this relay out because it seems like a mistery. This type of setup is very simple to duplicate, even with a common everday SPST relay. And I kind of like the 'trick' operation. Just my 2 cts.

HTH

Randy