Another Electrical thread... w/pics

[b.walker5]

Nice write up on meter use TC but I will correct you on one small point. Current is not "sent" by the meter. Current in a circuit is drawn by the load on the end of it, in this case the meter itself. Voltage is applied to a circuit but current is drawn.

Most DMM's should have an audible continuity test function, which is often enough to determine if a circuit is complete with no broken wires. You dont get a resistance value but it's a good place to start.

Randy. As an old school electrician I agree with you advocating for analog, I still use an english AVO, but for anyone buying a meter today, unless you want to buy 2, I would thoroughly recommend buying digital. Your absolutley correct in your comment about trying to measure cranking voltage on a digital but due to the high likelyhood of a meter being used on electronic circuits these days it simply doesnt make sense for a novice to buy analog.

[randy]

I give up.

[skids]

Nice write up on meter use TC but I will correct you on one small point. Current is not "sent" by the meter. Current in a circuit is drawn by the load on the end of it, in this case the meter itself. Voltage is applied to a circuit but current is drawn.

For ohms, I think the meter provides the potential (voltage), and reads the corresponding current to convert the figure into an ohms reading on the meter.

I am with Randy for using the analog for some things, like testing the voltage regulator/rectifier. Some meters don't have the juice to open the diodes and can lead you to believe that they are bad. I do tend to use my digital for the quick and dirty stuff though.

[T99Ford]

Oops. I will repeat that I wsn't trying to stir the pot, which is why I did not say that an analog meter would not work. The analog meter would work fine on these bikes. I just believe that if one is going to buy a meter, get one that will do everything. I was looking at the Fluke website (one of the premier electrical test equipment mfgs), and though I may be wrong, did not see any analog meters at all. My Fluke 88V can measure in real time even during a cranking test on a battery (actually measureing voltage drop across a starting circuit, though I rarely perform this test since there are other (more accurate) ways of testing all of the components used in this test. Additionally, the DMM can log high, low, and mean numbers during any test. I don't even have to see the meter to know what peak numbers are. And don't forget the audible continuity tester! In diode testing, the meter does not "open" anything. It sends a current through a diode, and then measures the current drop across the junction. Not only does this test let one know that the diode is working, buit it will produce a forward bias value to let one know the condition of the connections within the diode. This meter is 10,000,000 ohms/volt (ten million ohms/volt) with a margin of error of 0.1 %. (As opposed to 100,000 ohms of an analog). This meter reads 19,999 times/ 3 sec in high resolution mode, which I believe to be plenty accurate, and as fast as any analog (certainly faster than I can see)
I could go on, but won't, to keep the peace. I believe the current DMMs to be far superior to the analog units on almost every count (the exception being for current flow through the meter for amp readings-the DMM is limited to 20 A). An analog will work on the old XS. If you have one, use away! But if you are going to buy one, go for one you will be able to use for anything.

[tw1980]

sorry joe

Joe we hijacked your thread.But it looks like you got a lot of good advise.At any rate weather you learn to use an analog meter dig meter or a test light.It looks like you have a lot of work to do.Please keep us posted on your progress. If you need more help I'll try to stay on subject. Terry

[T99Ford]

Roger that, Terry!

[Geezer]

That's exactly why an analog meter is the best instrument for troubleshooting these bikes, they are for the most part all electromechanical in design.

I could not agree with you more.

Geezer

[joebus]

So quick Update...

I got that melted connector removed and everything connected nice and clean. While doing some more inspections of the fuse wiring I noticed that a red wire was connected by a spade fuse connector with a brown wire???? Then on another connection a brown to a red. I dont know electrical but to me this just has to be wrong. You can see it in the first pic. I have been playing with the meter trying to learn its functions and it looks like those two lines might be the problem. Shows no current going through i think...

[TopCatGr58]

Hey Joe,

I don't know if you have downloaded the manuals that Catatonic Bug has offered, or seen the wiring diagrams in the LINKS section, but according to the wiring diagram for the 79SF, the dark solid red wires at the FUSEBLOCK should go together with a 30 amp fuse, it's the MAIN FUSE!

The other brown wires should be connecting to red/white wires. One brown/Yellow set of wires connect to each other, for the turn signals.

Hope this helps!? T.C.

[joebus]

Ok, thats odd to me but i know nothing about electric so it does not surprise me at all I should have some time thursday to dig a little more into it. I suck at reading the diagram, but does the turn, headlight, and starter all run to the same fuse?

[DiverRay]

I suck at reading the diagram, but does the turn, headlight, and starter all run to the same fuse?

They DO all run through the MAIN FUSE, they then split off, and the headlight, turn, and IGNITION all have their OWN fuse. IIRC, they are ALL brown wires. The thing to look for is the brown wire at the ignition switch. It can get hot and melt/corrode the connection, and cause all kinds of problems.
If you know plumbing, think of electrical as high pressure side. You need a complete pipe to get the water to go where you want it. The colored wires are just different pipe connections, all from the same source.

[joebus]

I opened up the controls and there was some rust but the wire soldered on the back end of the started button looked great. Is there a way to by pass the button to see if that is the problem?

[John]

You can just short the blue/white starter wire to ground to see if the starter will engage. Check inside the switch housing for a small black wire that should be hattached to the inside of the housing by a small screw in the area of the housing where the wires entire the switch housing. This is the ground wire that completes the starter circuit. The start and horn buttons are not grounded through the handlebars.

[joebus]

So quick update. I can hotwire the bike to get it started. could test it just for a sec because if I wake our sleeping baby my life would be over so i tried to remove the ground wire screw so i could clean off all the rust and i cannot get the screw out. Every bit tries to strip the screw...Oh well. I went trough and cleaned up every ground connection i could see on the bike. Still not helping. I took out the headlight and i see about 5 open connections. I think the PO had a fairing on it and took it off and put a much larger headlight and never put the turns back on in the front. I am guessing i have a grounding issues somewhere but i am not having much luck. I will get back in it on saturday.

[joebus]

So hotwired the bike to start and then the headlight started to work and the turns started to work, and even the freaking starter button started to work. I guess it just needed its butt kicked before it would start. Each header got hot so they are all firing up. I just now need to check the plugs and change the oil because I did the second gear fix since the last season. I just hope it will fire up from here on out!