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'80 GS450 twin, electrical issues

  • Thread starter Thread starter Trevor76
  • Start date Start date
Yeah I put a little dielectric grease on everything too, cleaned the horn connections with a wire brush. Everything that I rewired or repaired I did with heatshrink connectors and then tested for continuity...

I wonder if I am missing a ground connection somewhere.

I should have some time this evening to work on it, wish me luck!
 
Yeah I put a little dielectric grease on everything too, cleaned the horn connections with a wire brush. Everything that I rewired or repaired I did with heatshrink connectors and then tested for continuity...

I wonder if I am missing a ground connection somewhere.

I should have some time this evening to work on it, wish me luck!

Sounds like you did the right things there :)

Let's hope it is something like a missing ground... good luck!
 
Regarding ground wires, I just remembered that the stock rear signals had a wire with ring terminals at each end, with one end bolted to the signal stalk and the other end to the frame...

I didn't fit such a setup to the new signals, usually the signals just ground to the frame through the mounting hardware, right?....

I doubt this could be the issue, but I'll try anything at this point.
 
Hmmm... I think the ring terminal goes around the thread of the signal stalk and then there's a bullet that goes into the harness.

If I remember correctly the ground for those is actually with the rear brake light switch...
 
One of my rear signals had a ring on each end which I thought was strange.
The wiring diagram shows each signal being grounded to the frame and I wanted to clarify that this was accomplished by the metal stalk?

Anyhow I had some success last night. I just took the starter solenoid out of the equation and ran the fused line directly to the battery positive. Turned the key and sure enough I've got a headlight, brake light, signals and dummy lights.

The signals would not blink, however. They would simply stay lit. I've heard of this happening with LED lights but these are the standard dual filament type.
I tried two different relays, same result.

Also no lights behind the speedo and tach gauges.

No horn either.

I'll see if any of these issues are rectified when I start the bike and have the engine running, I have to pick up a new length of heavy gauge wire to make a battery positive cable -that one I had pictured earlier was too thick and won't allow me to fit the battery in its cage.

I think now that maybe I misunderstood the entire time what I was supposed to do with that fused wire -I thought that it tied in at the solenoid, not the battery itself.
So I had a lead running from battery positive to solenoid, and this fused wire running from solenoid to main harness, so that there were two ring terminals on the solenoid's post.
Maybe that IS what you guys were telling me to do, but for whatever reason I wasn't getting a good connection there:confused:

Actually I just looked at the schematic and that's EXACTLY how they've got it going on in the original setup so I really don't understand why it's not working for me...

http://www.bikebandit.com/1980-suzuki-gs450et/o/m6029#sch265782

(sorry for the link, can't get the schematic to copy/paste)

If you look at that drawing you'll see that part#8 is what I'm trying to replicate.

Also, I have part#7 accounted for -obviously it is the negative battery cable with a ground wire branching off of it -but what is #10? Yet another ground wire? Where does that one ground to?
:confused::confused::confused::confused::confused::confused::confused:
 
10 is listed as ground wire body/earth

8 should be going to the starter relay and the fuse
Alpha Sports shows the discontinued items and is easier to link to.
Expensive to buy from though

02.gif
 
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Cool, thanks. I think maybe Bikebandit have somehow made it more difficult to link, I used to do it all the time when I was rebuilding the Honda.
And the fact that they don't list discontinued items is a drag as well, so I think I'll just replace them with Alphasports in my bookmarks.

So...basically there are a total of three wires coming off of the battery negative, one going to the starter motor and two of them to ground...do both of those grounds go to the same point?

Currently I have the ground wire from the negative lead, as well as the ground wire from the harness, bolted into the frame above and to the left of the battery. There is a hole in the frame there that appears to be for that exact purpose.

The way that this drawing shows the two ground wires coming off of the battery together leads me to believe that they are meant to bolt in at the same location, so I'll rig up another length of wire and do the same...

My question is, WHY? Why are there two ground wires travelling from the battery negative to a common ground point? Is it because the one tied into the battery negative is being used to ground the starter motor?
 
Cool, thanks. I think maybe Bikebandit have somehow made it more difficult to link, I used to do it all the time when I was rebuilding the Honda.
And the fact that they don't list discontinued items is a drag as well, so I think I'll just replace them with Alphasports in my bookmarks.

So...basically there are a total of three wires coming off of the battery negative, one going to the starter motor and two of them to ground...do both of those grounds go to the same point?

Currently I have the ground wire from the negative lead, as well as the ground wire from the harness, bolted into the frame above and to the left of the battery. There is a hole in the frame there that appears to be for that exact purpose.

The way that this drawing shows the two ground wires coming off of the battery together leads me to believe that they are meant to bolt in at the same location, so I'll rig up another length of wire and do the same...

My question is, WHY? Why are there two ground wires traveling from the battery negative to a common ground point? Is it because the one tied into the battery negative is being used to ground the starter motor?

I wouldn't replace, just add a new bookmark, and looking now at my wiring harness I can tell that the PO has made at least one modification to it, probably more. However it was working properly when I started taking the bike apart and I have taken alot of pictures along the way in hopes of making this useful to others. Still taking some even ;)

That being said what I have off the negative terminal is one wire going to the bottom of the engine for ground. and one going into the wiring harness near the rear brake switch which is also connected to the same ground screw on the electrical plate as the igniter ground. in the harness I've traced it back as far as being the common ground for the turn signals.
there is also a connection on the frame next to the negative terminal on the battery that is connected to the other side of the bike to the electrical plate lower left mounting screw.
On the positive I have one connection going from the + terminal to the starter relay and the fuse and that is all. the other end of the starter relays is to the starter motor.
No negative connection to the starter relay.
My rear turn signals have one wire and then a terminal connector around the bolt on the stem that is connected to the wiring harness ground.
Let me know if you want any pictures of that or anything else.
Thanks!
 
Thank you, I'm going to make a new positive cable tonight and see where that gets me.

Maybe I can fire the bike up and see what lights up and what won't.
 
Ok I'm only half awake and this is probably a repeat of some of apoplectic's stuff, but I'll stick it here anyway:

The thinner ground wires from the battery should go to the frame and the electrics plate.

The thick ground wire should go to the engine and should be terminated under one of the crank case bolts (this is to cope with the return current from the starter motor).

(If I was you I would do some modification to the electrics plate to make sure everything possible grounds to the same grounding point as the wire that goes back to battery negative)

The thick positive wire should go to one terminal on the starter solenoid.

The thin positive wire should go to the inline fuse.

The other end of the inline fuse should go to a red wire with a female bullet connector that comes out of the harness at about the same point as the yellow/green starter solenoid trigger wire.

The reason your indicators won't be working could be either not enough voltage or a bad ground or both. I had both issues on mine when I first hooked them up.

The horn could be simply that it's had enough. There is a thread or an article somewhere around on how you can repair them.
 
Okay, some more progress tonight:

All battery wires are now wired in EXACTLY as Pete has described above.
On the electrics plate the R/R, Ignitor, and main harness are all grounded to a single point, where the new wire I added tonight is in turn grounded and leads back to the battery negative.

As I write this I realize that the solenoid isn't grounded to anything, other than through the connection to the electrics plate itself...

I made a new positive battery lead with 10GA wire for the main line and 12GA branching off to meet the fuse. These two wires are crimped together with a battery terminal connector so that the whole thing closely resembles the stock setup (with the exception of the blade fuse in place of the glass fuse of course).

Turn signals are flashing now, albeit weakly. I replaced the stocker with one that I've had laying around for a few years. Also I cut the connection off of the wiring harness and spliced in the connection from the original harness -it just looked to be in better shape.


The flashers won't work when I turn the high beam on so Pete's "not enough voltage or a bad ground or both" theory sounds spot on.

Still no lights behind the tach or speedo, but the turn signal indicator, HI/LO, neutral and oil warning are all lit...(why was the oil light lit?)
This may be another indicator of low voltage as I assume that it takes more power to light the tach and speedo than the dummy lights...or maybe the bulbs are just burnt out.

Also I pushed the bike through all of the gears and the corresponding lights all worked.

Horn still is not working, I think it has simply given up the ghost and am not suspecting the wiring at this point...assuming that it is the horn itself then that means that all left-hand control are wired in and working properly except for the light switch, which for some reason is stuck in the "on" position.

Still no magic when I push the Start button, so I need to remove the right-hand control housing. Last time I tried to do that I stopped because I found that the mounting bolts were completely stripped. I ended up just grafting on the connector from the replacement control that I bought, as that one looked really awful and sun faded anyhow.

The solenoid is working, remember it is that brand new one from Rick's. I accidentally crossed both posts and in effect "jump started" the bike, giving myself a fright in the process...:eek:

And all of this experimentation began with a fully carged battery reading 12.something volts.

So, the issues seem to be low voltage, possibly still a bad ground (do I need to ground that solenoid better???), or maybe a
bad wire/connection within the right-hand control box.

I decided to leave the battery in overnight, and to check its state of charge tomorrow night. I figure it it goes dead in 24 hours then that's a sure sign of a bad ground/slow drain...right?

Any other theories?

Thanks guys, I think I'm almost there:D
 
12.something is pretty vague. I think less than 12.5 is no good. Are you sure the battery has a good charge? and did you ground to the engine and harness as well? or just the electrical plate and frame? I am having a heck of a time getting a picture of where my engine ground is but if I have time tomorrow I'' try to get a picture from underneath.
 
Ok, that definitely sounds like you're making good headway!!! :D

So at this point the main grounds should be covered off as long as where you've attached them isn't a painted surface and isn't corroded or anything like that.

The starter solenoid's body is the ground on the stock solenoid, so it's probably the same with your replacement one. That leads me to think that maybe those mounting points are painted and it's not grounding properly?

As for your gauge backlights not lighting up, that could simply be blown bulbs in there, I replaced mine with LED's due to having an intermittent issue at one point.

To test your horn wires, simply put a multimeter across the two terminals and hit the horn button, should show 12v while holding the button down.

Your oil light absolutely should be on when the ignition is on and the engine is off. It's actually an oil pressure (or lack thereof) indicator, so it will turn off once the oil pump has pressurised the oil system with the engine running.

There's possibly still an issue in your right controls, so I'd say pull it apart and clean time...
 
Can't remember offhand but I think it was like 12.62 or something? In any event the battery tender was showing a green light as was the LED on my multimeter's battery check feature.

I know, an actual number would be more scientific I just can't remember what it was reading but I will check the battery again when I work on it tonight or tomorrow.

If the gauge lights are indeed burnt out then I will most likely go the LED route, if I remember correctly there is a tutorial for that somewhere on Basscliff's site or maybe it was a topic here on GSR...

If I'm not mistaken they draw less voltage anyhow.

So next steps are to use either a small cutoff wheel or bolt extractor to get that R/H housing off and to see what's going on in there, and while I have the Dremel out I may as well throw a sanding attachment on there and buff the hell out of every ground point.

A quick question to clarify the procedure for checking the horn -am I setting the multimeter to the continuity (ohms) setting, or is it DC voltage? And does the battery need to be attached or detached?

Sorry for such rudimentary questions, still learning my way around a multimeter and the black art of electricity...

The upside of all of this poking and probing is that I am becoming intimately familiar with every inch of wiring on the bike.
 
Oh, that's funny! "Gauge LED modification thread"...is in Pete's signiture.
I knew I had seen that somewhere:rolleyes:
 
Hahaha mate it's all good, I've gone searching many a time only to see the thread or link right in front of me...

But the original gauge LED modification was by Matchless and is on BassCliff's site...

To measure the horn, you want DC volts and you'll need the battery in and I think the ignition and kill switches may need to be on also, can't remember if you can hit the horn with them off or not...
 
I have tracked the issue down to the right hand control box.

Last night after work I stuck the key in to see if the battery still had enough juice to run the lights, etc.

It did, and for kicks I tried the starter button -it worked! The problem seems to be a poor connection somewhere within the housing, and when I had moved the wires around the other night it must've made the connection.
The problem is not fixed, I still have to pull the housing off when I get a chance to mess with that stripped bolt. But at least the issue has been identified.

While I had the solenoid firing I went ahead and stuck the tank back on and connected the fuel feed, thinking I would give it a go and see if I could get the bike running.

I set the petcock to "prime", and saw fuel trickling through the fuel filter but no combustion.
Used the choke but to no avail. And the strange part is that there was a smell very similar to rotten eggs coming from somewhere...that's a first for me, I'm guessing that it may be bad gasoline? I had drained the float bowls of the carbs when I removed the tank last month so there shouldn't be any old fuel in there, maybe the gas in the tank is bad?

Of course there may be issues within the ignition system, as I have replaced the signal generator, ignitor, and coils...and while I'm convinced that they are all wired in correctly that doesn't mean that all of this stuff actually works!
 
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I have tracked the issue down to the right hand control box.

Last night after work I stuck the key in to see if the battery still had enough juice to run the lights, etc.

It did, and for kicks I tried the starter button -it worked! The problem seems to be a poor connection somewhere within the housing, and when I had moved the wires around the other night it must've made the connection.
The problem is not fixed, I still have to pull the housing off when I get a chance to mess with that stripped bolt. But at least the issue has been identified.

While I had the solenoid firing I went ahead and stuck the tank back on and connected the fuel feed, thinking I would give it a go and see if I could get the bike running.

I set the petcock to "prime", and saw fuel trickling through the fuel filter but no combustion.
Used the choke but to no avail. And the strange part is that there was a smell very similar to rotten eggs coming from somewhere...that's a first for me, I'm guessing that it may be bad gasoline? I had drained the float bowls of the carbs when I removed the tank last month so there shouldn't be any old fuel in there, maybe the gas in the tank is bad?

Of course there may be issues within the ignition system, as I have replaced the signal generator, ignitor, and coils...and while I'm convinced that they are all wired in correctly that doesn't mean that all of this stuff actually works!

Cool! Good to hear you got some action :D

While you've got it apart, spray contact cleaner on everything.

The starter button contacts on mine were black and cleaned right up, same with the contact areas for the kill switch.

You'll need to test for spark properly too, and don't forget if your floats are dry it will take a bit before it'll suck in enough fuel to kick over.

Not sure on the rotten egg smell but if that fuel's been in the tank for any more than a couple of months I'd probably turf it just to be sure...
 
So I had to detour for a few days, dug up an old thread on starter motors and it seems mine is a goner. Weird, because the starter worked when I brought this thing home.

Maybe I burned it up trying to start the bike over and over.

So I bid on one on Ebay, and won. $35 plus shipping, for one that seems to be in very good condition. A nice price but man costs are REALLY getting out of hand on this project. So today I put together a list of all of the stuff I have removed from the bike and put an ad in the for sale section, hopefully I can get a little back.

In other news I pulled the gauge cluster off and sure enough the bulbs behind the gauges are burnt out. So I will go to Autozone or NAPA to find replacements, and may go the LED route.

I was finally able to work the rightside control housing free and cleaned the contacts as best as I could with contact cleaner and a little wire brush. Lots of funk and cobwebs in there, much better now.

Also, I replaced the headlight lamp with a Xenon 60/55w bulb, as I had an extra one that was originally on the Honda.

As for that rotten egg smell, another member commented that batteries often smell that way RIGHT BEFORE EXPLODING...that has me a bit freaked out, and I'm hoping that with a new starter motor in there that I will never smell that smell again.

Otherwise...I may be in the market for a new battery, and if that's the case then this project gets shelved until springtime.
 
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