new battery woes

[skids]

No, that is NOT normal. Any relay should be off with the key off. Something is amiss there. The other thing is that a relay is powered with lower amps on the primary side and higher amps on the output side.

is that relay a stock headlight relay? If so, it shouldn't be powered with the key off. If it is a stock "latchable" relay, it shouldn't even light the headlights until the alternator is spinning, then it is "latched" to keep the headlight on. If that is the stock headlight relay, I suspect someone has rerouted some wiring. Maybe the diode was shot and they tried their best to make the headlight work?

[Blank Slate]

Thanks Sid.

So I did the 2,000 rpm test to see if voltage changed. it started out at 12.49 and got as high as 12.59 and stayed there.

[Blank Slate]

Should I just buy a couple of relays from Andreas as backup?

Is it more likely the relay is shorted or something else on the bike causing relay to overheat?

[skids]

Should I just buy a couple of relays from Andreas as backup?

Is it more likely the relay is shorted or something else on the bike causing relay to overheat?

From post No. 46: No, that is NOT normal. Any relay should be off with the key off. Something is amiss there.

If the thing is getting hot because it is energized even with the key off, a replacement relay is not going to help. I don't remember the reserve lighting unit (headlight relay) looking like that... Someone has either run a hot wire separate from the key switch, or the key switch is faulty in the off position. Did you give up on the multimeter? Did you pull fuses and check one at a time for volts with the key off?

[Blank Slate]

i know i need to get to work on post 32 and 35. it’s been a busy weekend so far. sunday i have all the time to go through fuses, diodes, to find the short!

[Blank Slate]

and i dont think the relay is the problem because i did a little test. i charged the battery, it went up to 13.4. then i hooked it up to the bike, but disconnected the relay. a few hours later my battery was 12.99. its losing voltage somewhere

[skids]

I'm pretty sure it's a 79 wiring harness. the only things that are 81 are the engine with the TCi for the 81 engine. everything else is 79 special.

If it has the 81 TCI it also needs the 81 pickup coils and assembly. Been there, done that.

[Blank Slate]

You're doing fine, even excellent!

Almost all of the electrical system should be completely dead when the ignition switch is off. Before you remove the fuel tank, just pull all of the fuses except the Main fuse, then hook up the battery to see if anything is clicking.

If nothing clicks, put the fuses back in one at a time.

i removed the 10, 20, fuse and it was still clicking. Then I removed the 30 and clicking stopped.

[Blank Slate]

ok dictionary.. what is a diode... a semiconductor device
what does it look like?
i read the link you provided but i need to read it again slower to understand.

Disconnect the voltage regulator/rectifier and check the diodes.

[url=http://www.xs11.com/forum/showthread.php?t=29251]
link: http://www.xs11.com/forum/showthread.php?t=29251

XS11 .com Forums > Idle Talk Forum > XS11/XJ11 Discussion
Best way to check if a regulator/rectifier is going bad?[/url

[skids]

ok dictionary.. what is a diode... a semiconductor device
what does it look like?
i read the link you provided but i need to read it again slower to understand.

You would be better to look up how to check the volt regulator rather than understand what it looks like inside!

In short, the VR converts 3 phase alternating current to DC current by means of a “bridge rectifier”. This has diodes that are like one-way valves. The VR also limits the field coil so that the output from the alternator is no to high (or it might just send extra voltage to ground, not sure). See? There is more inside that thing than you want to know.

One thing you want to check that is easy. Turn on the key and put something made of iron against the right side cover to see if you have magnetic field there. You should.

[skids]

After checking the field coil, if you haven’t already, you definately need to check that clip behind the fuse panel for corrosion. It is a very common issue. The clip has 3 white and 1 yellow (might look white). Any melting of the plastic clip is indicative of arcing and needs to be fixed! If your tach is not working, you are likely not charging. If your headlght is not coming on, there is also a chance that one of the wires is not making a good connection in that clip.

Did I miss something you posted about that relay you hung off of the front? I wonder if the PO has rigged a relay for the headlight because the alternator was not sending a signal to the reserve lighting unit (relay). You CAN use an aftermarket relay for the headlights but it has to be done correctly and you will lose the automatic witching of beams high to low and visa versa if a filiment burns out. This is extra info and is not the root of the problem if your charging is kapoot!

[Blank Slate]

yes there is a magnetic pull on metals when i turn key on. it’s not crazy strong but it’s there

[3Phase]

yes there is a magnetic pull on metals when i turn key on. it’s not crazy strong but it’s there

Unplug the two connectors for the voltage regulator/rectifier and see if the headlight relay still clicks when you connect the battery with the ignition switch off.

If the headlight relay stops clicking then you have a bad regulator/rectifier or a short in the charging system and the battery is discharging back through the alternator.

[TopCatGr58]

Thanks Sid.

So I did the 2,000 rpm test to see if voltage changed. it started out at 12.49 and got as high as 12.59 and stayed there.

Hey there Blank,
Nobody commented on these findings, they are NOT GOOD. The voltage should rise up to ~14.5 V at 2500 rpm, so that's a strong indicator that it's not charging. However, what SKids did say is that the 3 white/1 yellow wire connector BEHIND the fuse panel plate is where you need to check for melted plastic connector. With corrosion, resistance in those 3 wires will get quite hot to the point of melting the plastic.

You reported a magnetic field on the side of the ALT, so that's a good sign that the field coil is getting energized. But the 12.59 @ 2k rpm isn't good, means that the ALT isn't putting out much power, possibly due to corrosion in the 3 white wires, but also could be damaged RECTIFIER.

BTW, it's normal of a fully charged battery to drop a few tenths volts after coming off of a charger. You might try charging again, then just leave off charger, check Volts immediately and again a few hours later while still on the bench, you'll probably see the voltage drop a bit then also.

Good luck, keep working on it.

[3Phase]

If the field coil was not working then the voltage would drop and never rise even slightly above battery voltage.

The running voltage is low because one or more of the rectifier diodes is bad and at least one is shorted so it's killing the battery when the engine is not running.

Disconnect the voltage regulator/rectifier. If the headlight relay stops clicking, replace the regulator/rectifier.

Here's the schematic from the shop manual.