Negative sparks when connecting - short somewhere
 

My 98 Hawk sat for a couple weeks while I was under the weather, and when I tried to start it, the battery was completely dead (didn't even register a bump on a multimeter).

The battery is only a couple months old.

I recharged it and set about bolting it back in. Positive terminal first; then when I was attaching the negative, I got sparks. I left it on for about ten minutes and then decided that wasn't the smartest thing to do.

So, I went back out to the garage to take the battery back out, and I noticed that the right-side subframe (that supports the seat) had actually gotten very hot!

Obviously I have a short somewhere. Any suggestions on where to start looking first? I'm hoping it's a bad ground from the actual negative cable, but that might be wishful thinking.

I feel for you. I HATE electrical problems. Check both negative and positive cables from the battery to be sure the insulation on them is good.

So do I. I had an 82 Kawi GPz 750 with that kept blowing fuses. I did a lot of voltage drop testing, unwrapped a bunch of wiring harnesses, replaced and cleaned switches and connectors, etc. I finally got the problem fixed, but I never did precisely isolate which connectors, switch or whatever was the source of the problem.

Sigh.

I did the same with my old VX800 at one time. good luck with the multi-meter. Hope you find it quick.

Negative ground from battery is solid. Damn.

A bit more information; if this sounds familiar to anyone, lemme know what you found. Turns out that the green ground wire leading to the regulator / rectifier is getting hot within 30 seconds or so of connecting the battery. Bad R/R or something else?

A small spark from the battery terminals when connecting the cables is completely normal. I wouldn't give it a second thought!

If that were all it was, I'd be ok with it. But I'm getting quite a bit of sparking, and as I just wrote, extreme heat buildup in the wire leading to the R/R -- and eventually heat in the seat subframe itself. So I think something is not right here.

Did you check your power lead to your ignition switch? The switch should have everything shut down.

Not yet, but that's a good idea. The fact that the wire to the R/R gets hot within half a minute or so suggests there's a short somewhere -- the R/R itself may be fine.

What's going to make this difficult (among other things) is I can only leave the battery connected for a couple minutes at a time before things get too hot.

Disconnect the R/R and see if you still get a spark. If not, replace the R/R. If yes, keep looking.

If it is the OEM R/R I would test that first. Easy to do and very possible culprit.

Kai_ju, I unbolted the ground to the r/r, and still saw sparking from the battery. I then undid the connector to the r/r, and the sparking disappeared. Wish I wasn't so ignorant about electrical issues, but what does that tell me?

lazn, do you know of any instructions for testing the r/r?

Thanks all.

Sounds like I need the R/R, then. Just have to keep riding my Yamaha WR250 in the meantime. Just need to live without torque on demand for a while ....

I know you are past the point of diagnosing now for this problem, but in the future using the ammeter function of a multimeter is what I use for something like this. On a later model superhawk with the lcd meters you should see only about 50-75 milliamps max (.050-.075 A) on an ammeter connected between the negative batt terminal and its associated cable connector. Anything above that indicates a short.

A time consuming but logical and sure fire way to narrow it down is momentary disconnection/reconnection of various electrical connectors to isolate to an area. (Obviously you'd have to do that in short bursts if it's drawing 10 Amps or more!!)

Hold on there, nothing is final until our resident guru, Tweety, gives his input. Wait for it...

Time for an R/R swap.. ebay a MOSFET one and do the conversion.

Try to get one with the plugs included (I lucked out that way) or if you can't either get a premade kit from Eastern Beaver, or if you are comfortable soldering the individual plugs end up cheaper from Jasonmotoelectrix

Well ... I WAS in fact trying to do exactly what your said with the ammeter function of my multimeter, but somehow I bumbled getting the probes in place and burnt out the internal fuse for the ammeter. The instructions mentioned something about "discharging" before doing this, but I honestly don't know what I was supposed to discharge.

Good advice, though.

I was thinking along those lines ... Jasonmotelectrix has a complete kit for around $120 on eBay at SHINDENGEN MOSFET FH012AA REGULATOR/RECTIFIER KIT | eBay .

Just got this MOSFET R/R and hardware yesterday. I'm anxious to put it on, but it's quite a bit larger than the stock one. Has anyone installed one of these on there Superhawk before, or something similar in size? Where did you put it?

That's the one I got, I mounted it in the stock location, rotated to fit, I used only 1 bolt though..

The hard one to fit is the one with 4" fins on it..

Great, thanks for the info!

It's done
 

Turns out it was in fact the R/R. Thought I'd post a few pics of how I attached it.

I bought the MOSFET R/R kit on eBay that I mentioned earlier in this post. A bit more at $119.00, but I wanted to have all the connectors, etc., ready to go. They seem very solid.

I was able to put it where the factory R/R had been, and reused one of the already drilled holes (but had to use a different bolt because the original one was too short for the new R/R).

So far, so good: no sparks, no frame getting hot. Thanks for the advice I got here!