MAJOR electrical problems on my 1977 kz650

my bike ran fine last Saturday.I went to start it this past Sunday,when i pushed the electric start push button,nothing happened.i have lights,turn signals,hazard flasher,brake lights.when my lights are turned on,and i turn the kill switch on,my turn signal lights turn a dimmer color.i took the right side cover off where the fuse box is.the main 20 amp fuse is good.where the 2 main white wires come out of fuse box,they were hot/real warm at the connection.i got the test light out.with the key on,both sides of the fuse clip were hot with juice.where the connections where the white wires plug into each other,they were hot,i touched it with my tester and BOOMMMMMMMMMMMMMMMMMM.a real loud noise,like a M80 went off.i first thought the battery blew up on me,but the battery is still in one peice.the noise came from that area,under the battery,there is a aluminum finned box under there.any ideas why the starter button quit all of the sudden,and why the explosion,and what the problem is.the bike was fine one day,and now i have a major diaster,and do not have any idea what caused it,or how to fix it.any help would be very appreciated.i was told that if anybody would know,that it would be someone on this website.thanks!!!!!!!!!!!!!!!!!

neh810@yahoo.com

A firecracker pop might have been a fuse blowing or it could be that a spark ignited some gas coming from the battery.

If yu see indicators dim when you turn something on, that something is drawing a ton of current.

when my lights are turned on,and i turn the kill switch on,my turn signal lights turn a dimmer color.

Wild guess, but I would look at the coils or the wiring to them for a short of some kind.

Under the battery box is the usual mouting place for the regulator/rectifier. You'll have to remove the battery and remove some battery box parts to access it.

Some websites for stators/ regulator/rectifiers:

www.rmstator.com
www.electrosport.com (This website has a troubleshooting page)
www.customrewind.com
www.regulatorrectifier.com
www.ricksmotorsportselectrics.com
www.oregonmotorcycleparts.com

well really hot it sounds like you have a hot wire starting to ground out i cant belive your fuse didnt blow start with your button make shur its it pressing proprly on to the contactpoint and that it isnt crodedthen trace your wires back make shur nothings cracked or rubbing ,broke ,grounded out,exc. the test your starter but if you heard a boom test your i for got the name the black round thing that has rubber around it your positive comes off the battery to there and the negative that goes to your frame take a screw driver and tuotch them to gether if you rbike turns over then you have a wireing or button problem thats all i can give ya hope it helps

I think Mfolks nailed it: the regulator/rectifier assemby connects to the battery but has no fuse in series with it. A problem in it could draw a lot of current and no fuse would blow.

The alternators on most bike's of this time period ran wide open with the regulator/rectifiers converting the alternators A.C.output to D.C.,charging the battery and running the bike's electrical systems.

Any excess energy was converted to heat, disappated(sp) through the cooling fins.

There is/was no fuses on the charging system.

short between your rectifire and alternater usually behind the drive gear right buy where it goes into the alternater
pull the dive gear cover and have a look99% sure this is wherew the problem is.FAMOUS SHORT on these bikes

PS buy the sound of it switch to a good old dyna s eletronic ignition youll wish youd done that a million years ago.Through away the stock pionts

IF you wanna run a pionts ignition clean the contacts on the right side under the cover.Take a piece of fine sandpaper and fold it in half then put inbetween the contacts at the breaker and run it back and forth until the points are clean.put in a new capaciter then try that>I cant remember how many ohms the capaciter should be.but if you are gonna run points this is where to look.
PS get a dyna S way better idea

(1) would that cause nothing to happen when i push the start button in?
(2)where on the bike do i look to find that part and area ?

Welcome to Kzr neh810.

You didn't mention if you'd done anything to your bike prior to this happening.

Normally grounding out issues don't "just happen", there's usually something (most times something minimal) that caused it, ie: repositioning the switches on the h-bars, adjusting the headlight angle, moving the wire harness to get to the air filter, etc.

I had a similar issue a few years back on my '78 650. It turns out that when I replaced the OEM handlebars with some SuperBike bars I had placed the switches directly against the clutch and brake perches, therefore pinching the wires slightly. Eventually it wore through the wire insulation and----pow! Blown main fuse and HOT main wire to fuse box.

i did replace the handle bars,i have taken the switch housings off to make sure that nothing was showing or pinched.