Persistant Blow of 20A Main Fuse

That sounds interesting. I'll try that.

Newbie question: What connections do I need to make with my meter leads for the Amps DC test?

Did this all start to happen after you put the new style fuse panel in?
The connections on your meter? Most will have a separate 10 AMP hole to put the red positive probe into, then the black negative stays in the same hole. Turn the Dial to DC 10 AMP setting, then 1 lead goes to one side of the fuse, and the other lead to the other side of the fuse. IF you get a negative reading swap the lead around to change polarity. Your meter more than likely will be able to take 10 AMPs, but there is a fuse inside that will blow if you exceed this much, maybe 15 AMPs. There is another way to test for a short to ground, cheap, but may take awhile.
Get a spare 12v bulb with 2 test wires coming off of it, put it across the battery terminals and it should light up. This verifies the light works, now hook 1 end of the light to the hot 12v side of your main fuse in series, this means still using the fuse for protection, and the other end to the load side of the circuit. First without turning on the key, do a full, and I mean full wiggle test of the harness to see if it shorts. The light will come on/ blink if it gets a ground. You may need to have the tank/ side covers/ head light bucket/ seat open to access this. If it doesn't light up, then it would be on a circuit which is switched. Then back to unplugging and trying to see if there is 1 Item you can pin down. They do sell a short circuit finder, there is a meter that can be run along the harness, and a circuit breaker with a buzzer that takes the place of the fuse.This buzzes when the short happens.
As far as the 2 yellow wires getting super hot, no this should be a minimal amount of heat. the heat is from resistance in the connector, and more than likely the wiring that's close to the plug. You may have to clean the connector, but more than likely the wires are damaged and you would need to either cut back to good wire and splice, or replace the wire completely.

alexnelson wrote:

As a side question, is it normal for the two yellow wires coming from the alternator to the reg/rec to be super hot? And if so, could they be getting hot as a result of anything other than the alternator?

They should not be super hot. One thing to always remember on old bikes: hot wires and hot fuses don't always mean excess current, it can be corroded connections. The associated voltage drop across a corroded or dirty connection creates a ton of power dissipation.

The alternator wires may be getting hot from too much current, or conducting heat being generated in the regulator/rectifier assembly.

alexnelson wrote:

That sounds interesting. I'll try that.

Newbie question: What connections do I need to make with my meter leads for the Amps DC test?

Unless you have a meter that can measure >30A, don't try it. You'll blow traces in the meter.

Good point Bounty
Keep in mind.... Most DVM meters are designed with internal fuse ratings of 20Amps for AC/DC current measurements.....

NOTE I said most so as Bounty mentioned, read your DVM manual no doubt....

Same time, his situation is not blowing the fuse right away so most likely not a dead short thus >20amp current flow....

To answer your question... With meter set for DCamp measurement, 20 amp range or higher.....
Your DVM manual should inform you of exact DC amperage configurations but useally conifigured as such.....

Oh god, here we go.... Electron flow is negative to positive.... Engineers are taught the oppossite...
I look at this way, as long as it is flowing to spec I'm good.... :laugh:

* (+) to fuse leg.
* Otherside of fuse to Black DVM probe.
* Red probe to switch/ignition switch....

What's your measurement?

BTW, have plenty of 20 amp blade fuses ready.... It will take a couple blown fuses to figure out....

One of 2 ways to go about it...
1) Start as mentioned with bare minimum connected for running....

2) Start as is presently connected & d-connect one at a time...

OMR

Motor Head wrote:

Did this all start to happen after you put the new style fuse panel in?

No. The new fuse panel was one of my many attempts to fix the problem.

It all started when I opened my headlamp to tighten the nut holding the left signal light to the headlamp housing. Now you're all thinking, "Well, your problem must be in there!" Maybe it is. But like I say, I've had then thing open so many darn times and can't see anything wrong.

I took my tac and speedo off a while ago. I rode for at least a couple weeks with them off before this happened though.

My point is I've been all over the bike and I can't see the problem with my own eyes so a method of testing is all I have to go on.

bountyhunter wrote:

alexnelson wrote:

That sounds interesting. I'll try that.

Newbie question: What connections do I need to make with my meter leads for the Amps DC test?

Unless you have a meter that can measure >30A, don't try it. You'll blow traces in the meter.

This is my meter.
ca.fluke.com/Fluke/caen/Digital-Multimet...-77-IV.htm?PID=56126

mA-10A

Guess I can't do the Amps DC test.

Huh...?

First page of your link....
10 Amps continuous (20A for 30 seconds)

Same time, nice meter you have there so get yourself a clamp type current meter then you won;t have to worry about it....

Or better yet, they do have Fluke Current Clamp adapters that plug and play (measure) for the fluke DVM line of products.... Spendy, well yeah but it is a Fluke after all and you want to fix your baby right...

Something caught my eye in your last postings....
Disconnect the headlight harness plug and re-test....
Fuse blowing?

Ah crap... I said the word Electron flow and ole Plumm got a chubby..... (Wood).... :laugh:

Something caught my eye in your last postings....
Disconnect the headlight harness plug and re-test....
Fuse blowing?

First thing I'm trying when I get home . . .

Alex.... D-connect the instrument cluster harness connector as well and re-test...