Dash/lights/starter won't turn on, battery seems fine.

[BBoh21]

Hey guys, new 79 GS550E owner here. The other day my bike shut off when I came to a stop at a stop light. It seems to be an electrical issue. I've been doing tons of reading on the mechanical side of things, but zero on electrical, so I'm a little out of my element here. I have a multimeter that reads the voltage on my battery at ~12.4 or 5 (not at home currently and can't remember the exact reading), so I believe my battery is fine? When I turn my key to the on position nothing happens. Dash, lights, when I try to turn the ignition, nada. So it would appear I have a fault somewhere directly after the battery, correct? I looked through a couple of BassCliff's electrical guides and he mentions a fault finding chart, but I can't seem to find it anywhere. Any help? Something super obvious I'm overlooking?

BikeCliff's website also seems to have a wiring diagram for tons of different bikes, but a 79 GS550E doesn't appear to be on there. Is there another model that I can look at that is on there with the same wiring diagram?

Sorry for so many questions, I'm a new bike owner who is eager to learn and trying to take in as much as possible.

 

[Steve]

Have you checked your (one and only) fuse? :-k

.

 

[GSCafe]

Have you checked your (one and only) fuse? :-k

.

Mine seems to be missing! The PO seems to have wired it out of the circuit. I still have the box that it came in and plan to address this. For me it was a small translucent box on the starboard side with red wires and a spot for only one fuse.

 

[tom203]

Mine seems to be missing! The PO seems to have wired it out of the circuit. I still have the box that it came in and plan to address this. For me it was a small translucent box on the starboard side with red wires and a spot for only one fuse.

If PO decided fuse was optional, be suspicious! This 425 diagram should be similar- shows how power flows from battery to fuse, etc
https://onedrive.live.com/?cid=2370B62DDF9F0C6B&id=2370B62DDF9F0C6B!1032&sc=documents&v=3

 

[BBoh21]

Have you checked your (one and only) fuse? :-k

.

I opened up my fuse box (I have four, not one) and looks like my 15 amp main fuse was blown. I won't be able to put a new one in until tonight to be positive but that should do the trick. So I just need to pick up a glass tube fuse that's labeled at 15 amps right? Any additional specs I need to make sure I'm buying the right fuse?

 

[tom203]

To BBoh21..... You got 4 fuses ? Your wiring is likely like this 79 gs850 not like the gs425 pen

http://members.dslextreme.com/users/bikecliff/images/1979_GS850GN_wiring.gif

15 amp fuse at autozone, is fine Make sure you get a few- you might need them to determine your problem

 

[Steve]

I opened up my fuse box (I have four, not one) ...

You have four fuses? :-k

You sure you have a '79?

What shape is your front master cylinder? Rectangular or round?
Do you have VM carbs or BS carbs?
Do you have points or electronic ignition?

I am betting that you have an '80 bike that was MADE in late '79 and some Bozo at the DMV office titled it as a '79.

.

 

[BBoh21]

To BBoh21..... You got 4 fuses ? Your wiring is likely like this 79 gs850 not like the gs425 pen

Yep, not in front of my bike at the moment so this may be wrong but I had a 15 amp main fuse, then three 10 amp fuses for ignition, lights, and turn signals I believe. The diagram for the 850 you just posted looks more accurate than the 425, but I'm still working on figuring out how to read those diagrams.

 

[BBoh21]

You have four fuses? :-k

You sure you have a '79?

What shape is your front master cylinder? Rectangular or round?
Do you have VM carbs or BS carbs?
Do you have points or electronic ignition?

I am betting that you have an '80 bike that was MADE in late '79 and some Bozo at the DMV office titled it as a '79.

.

The previous owner said it was a '79 and the VIN comes out as a '79 as well. It has a kick start and electric start on it, which I read that '79 was the last year they put on both. I can't speak off the top of my head as to the rest of your questions Steve (like I said, newbie still learning).


Edit: googled front master cylinder, if it's the front brake fluid reservoir on top of the handlebars like it seems it is, then mine is round.

 

[Brendan W]

The previous owner said it was a '79 and the VIN comes out as a '79 as well. It has a kick start and electric start on it, which I read that '79 was the last year they put on both. I can't speak off the top of my head as to the rest of your questions Steve (like I said, newbie still learning).


Edit: googled front master cylinder, if it's the front brake fluid reservoir on top of the handlebars like it seems it is, then mine is round.

This where the fun starts. Mine is 81 and has a round reservoir. Most likely a PO replaced it.

 

[Redman]

BBohp21,

Buy a pack of 15 amp fuses.

If it blows as soon as you put one one back in, before turn on the key: find the regulator/rectifyer ("R/R", usally on side or bottom of battery box, the aluminum finned thing) and disconnect it, see if next fuse does not blow. And if you want more evidence, plug it back in and see if the fuse blows.
Bike will run without the R/R connected, with a good main fuse, just will not be charging the battery, and running entirely off the battery.

.

 

[BBoh21]

BBohp21,

Buy a pack of 15 amp fuses.

If it blows as soon as you put one one back in, before turn on the key: find the regulator/rectifyer ("R/R", usally on side or bottom of battery box, the aluminum finned thing) and disconnect it, see if next fuse does not blow. And if you want more evidence, plug it back in and see if the fuse blows.
Bike will run without the R/R connected, with a good main fuse, just will not be charging the battery, and running entirely off the battery.

.

I take it this be to test if the R/R is the culprit behind blowing the fuse? The R/R regulates voltage coming from the alternator while the bike is running, and a faulty R/R would not regulate it and overload the electrical system causing the blown fuse... am I getting that right?

 

[tom203]

While you're checking out what Steve asked, try to determine if this bike appears to have separate rectifier and regulator rather than a combo unit that's found on later years.

 

[eil]

I had the same thing happen to me on my 850. Running fine, pulled up to a stoplight in a left turn lane, idled for a bit and then simply died. The main fuse had blown. Later I discovered that the PO had mixed up the fuses and put a 10A fuse in the spot for the main circuit (which should have been 15) and put the 15A fuse in the lights circuit (which should have been 10).

I guess what I'm saying in a roundabout way is make sure you have the right fuses in the right spots. And also know that fuses can go bad with age. My hypothesis is that the metal filament inside the glass is subject to vibration which weakens the ends where it is bonded to the terminals.

 

[Redman]

I take it this be to test if the R/R is the culprit behind blowing the fuse? ................

Yes.
SInce the fuse is blowing quite regularly, can disconnect the R/R to remove it from being able to blow the fuse.
Do replace the fuse, and the bike can run without the R/R, and if go a lot longer than you had before, well, then you can surmise the R/R is-has been-was the problem. Can run bike a long time, just are not charging the battery, but do need to get back to a charger.

........... The R/R regulates voltage coming from the alternator while the bike is running, .............

YES. The R/R is a regulator.... and....

Although a matter of definition.
Your bike has a stator, which is a 3 phase AC generator, and that goes to your R/R which is a seperate device, and that Rectifies the AC to DC and Regulates it to, say, 13.5 volts.
(and to further confuse things, GSes prior to say, 78, the rectifyer was a seperate device and the regulator was a seperate device)

An "alternator" is a name used to describe a device that is all that in one unit (mechanical spin goes in one end, and 12vdc current comes out the other end), which these suzukis dont have, but is common in automotive since the 40 & 50S and Honda mocykle sine the mid 70s and BMW mocykls for as long as I have known (some you can see it, looks rather automotive, belt driven and all).

........ and a faulty R/R would not regulate it and overload the electrical system causing the blown fuse... am I getting that right?

A fault R/R can fail in a few differnt ways:
1- have an intenal fault that shorts your DC power to ground, and blow the fuse as soon as it is connected. (the situation we suspect here in this case)
2- not regulte well so have way high voltage
3- have an internal fault that essentially shorts out the stator and burns out the stator.
4- not regulate well so have way low voltage (although that usally a wiring problem or stator problem)

Sometimes exhibits both symptoms 1 & 3.

.

 

[BBoh21]

Ok guys, so I just got home with some new fuses and something weird is happening, I'll try to my best to explain it. I put in the new fuse and checked all four to make sure they were fine with my multimeter. When I turned the key on nothing happened. I checked the battery with the meter again with the key on. After bouncing around for a bit it settled in at it's usual ~12.4 and the dash lights then turned on. When I tried to start it the starter clicked then the dash lights went back off. I checked the battery and it was bouncing around up anywhere from 50 to 100. If I meter on the battery it would eventually settle back down to its usual voltage again within about a minute and the dash lights would turn back on.

I repeated this process a few times with the multimeter on the battery and the same thing kept happening. However, if I didn't check the battery with the mutlimeter after trying to start the bike the dash lights would go off and wouldn't turn back on, no matter how long I waited. It was only until I checked the battery again with the meter that the dash lights would come back on.

Can anyone give some insight on what is happening here? It appears that putting the multimeter on the battery is completing a circuit? I'm really not sure what to make of this.

Here's a picture of what's under my right cover (fuses and whatnot) if that helps at all. I took off the fuse box cover, it's not missing:
http://imgur.com/z1RPI08

Steve was asking about points/electric ignition earlier, unless I'm mistaken it appears to be points ignition. I took a picture just to be sure:
http://imgur.com/UqD66w4

 

[Steve]

Yep, them's points. :encouragement:

Apparently you have a LATE '79, that started some of the features of the '80, as the factory manual does not show four fuses until the '80 model. All the other things you mentioned that I asked about verify it's a '79, though.

About the wonky meter readings: yes, the meter does "complete a circuit", but when it's used properly, it puts so liitle of a load that it does not affect the circuit. When the meter read 50 and 100, did it still show "volts", not "milli-volts"?

.

 

[BBoh21]

The meter reads at mV when it bounces around in the 50-100, not V. Didn't notice that the first time and had to go back out and check after reading your reply. So when I turn the key on nothing happens until I attach the meter, then then dial lights go on and it goes up to 12.5 V, then as soon as I try to start it it shuts back off and goes down to 50-100 mV. If I hold the meter on the battery it'll eventually go up to 12.5 V again and the dial lights come back on; if i don't, it'll stay shut off. Just rechecked the fuses and they're all still fine. I'm not sure where to go from here.

 

[posplayr]

Are you connecting direct to the battery before you turn the key on? Do that. Measure the voltage . Should be 12.5V or above.
The next step is to turn on the Key without cranking (this should give about a 7 amp load with the headlamp on)... What happens. Report the results.

See Quick Test in my signature.

 

[Redman]

The meter reads at mV when it bounces around in the 50-100, not V. Didn't notice that the first time and had to go back out and check after reading your reply. So when I turn the key on nothing happens until I attach the meter, then then dial lights go on and it goes up to 12.5 V, then as soon as I try to start it it shuts back off and goes down to 50-100 mV. If I hold the meter on the battery it'll eventually go up to 12.5 V again and the dial lights come back on; if i don't, it'll stay shut off. Just rechecked the fuses and they're all still fine. I'm not sure where to go from here.

I would say that touching the meter leads to the battery or battery connections should not effect anything, that is the electrical load of the meter (in voltage setting) is purposly small so it does not effect anything.
Maybe just the fact that anything is touching the battery connection is what is happening, such as maybe a bad battery connection. Try taking the cables off the battery, inspect, cleanup, and put back.

When you say meter is jumping around before it settles out, might that be the meter autoranging. Maybe you can select a more specific range, or maybe once it settles out there is a button you can push so it stays on that range.