Blows Main Fuse

[T mac]

Hi,
I have a 1982 Suzuki GS450L. I been riding it for 2.5 years now. But now the main 15 amp fuse blows. the bike will start up and go about 15 feet before it will blow, if it dose not blow right away. It seems that the ignition key works and will keep the lights on without blowing the fuse but the run switch will blow the fuse right away when I turn the switch off.

I had a problem with the fuse blowing last October. The fuse wiring heated up and melted the plastic off it, so I replace the wire and fuse with a new one.
Then moved some wires around checking connections and then the bike ran fine till now.
The bike seems to run when idling, it blows the fuse when I put it in first and go or turn the run switch off.
I do not have a book so any info is good. thanks.

[chef1366]

Get a multi-meter and check the voltage at the battery while running. If it is over 15 volts you need to replace your R/R or check the ground wire.

[BassCliff]

Greetings and Salutations!!

Hi Mr. T mac,

You'll need to start by checking, cleaning, and repairing every electrical connection and ground on the entire wiring harness, from headlight bucket to tail light including the fuse box and ignition switch. Clean the connections on the solenoid, the battery, and even that big fat ground wire that runs from the negative battery terminal to the bottom of the engine. I even cleaned my turn signal stalks. Run the ground wire from your regulator/rectifier unit directly to the negative battery terminal. Somewhere you have corroded connections that are causing too much resistance and excessive heat. Also check for melted insulation and bare wires that may be shorting to the frame. You may find some useful information on my website. Please help yourself.

Anyway, I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[T mac]

So today I tested the voltage at the battery when idling and it measure 11.9 volts. Also I clean almost every plastic wire connection on the bike. And now the bike will stay running even after the fuse blows, so idk. Next I will clean the metal clips that link the wires together. Thanks for all your input and info on the site.

[BassCliff]

Hi,

In your "mega-welcome" you will find a link to The Stator Papers. Utilize this information to learn about your charging system and troubleshoot why it is not charging properly.


Thank you for your indulgence,

BassCliff

[Mekanix]

Even when the main fuse blows your now running on battery power.

You mentioned that the Run switch would cause it to blow the fuse, I believe that powder from the battery goes to the ignition switch than to the run switch, then to the coils and then to the ignitor.

Something in that line will be drawing allot of current.

Either a bad coil or a wire partially grounding out.

Or it could be something else that is taking allot of power and the ignition system is just enough to put it over the limit.

You could try removing the fuse and using a multimeter set to AMPS in place of the fuse and see what it says when ON, at Idle, and higher RPM.

Also see what is taking all the power, Try disconecting your headlight and tail light and see if it drops significantly.


Good luck

[koolaid_kid]

11.9 volts is battery power, the alternator is not involved yet. If the voltage is 13 volts or above, then the charging system is involved. You might want to check it stationary and rev the engine until the voltage jumps above 13 volts, just to see if the fuse blows at that time or seems to be fine.

[posplayr]

Even when the main fuse blows your now running on battery power.

You mentioned that the Run switch would cause it to blow the fuse, I believe that powder from the battery goes to the ignition switch than to the run switch, then to the coils and then to the ignitor.

Something in that line will be drawing allot of current.

Either a bad coil or a wire partially grounding out.

Or it could be something else that is taking allot of power and the ignition system is just enough to put it over the limit.

You could try removing the fuse and using a multimeter set to AMPS in place of the fuse and see what it says when ON, at Idle, and higher RPM.

Also see what is taking all the power, Try disconecting your headlight and tail light and see if it drops significantly.


Good luck

I agree with a short, he should pull the tank and look for some physical damage to the harness. If it is a short it will be difficult to pin point without seeing the physical damage.

Taking things out of the circuit could help, but only if you can do it at the fuse box. Tmac: Do you have multiple fuses?

[T mac]

The bike has one 15 amp fuse for the whole bike. I have been going though the wiring harness checking connections and cleaned the wiring clips. The problem now is the bike wont stay idling to do the (flow chart tests) and the bike dies when I try to rev the engine. to test it.
I did run a ground from the batterys (-) to the R/Rs (black/white) wire. And the lites are brighter and dont dim when using the turn signals. Happy about that if I ever ride it agian.

Also last time the bike would stay idling for a long time without blowing the fuse I moved the spark plug wires around because I know the spark plug wires are wore and arc to the engine sometime (if its to close to the block). Could that be the problem bad spark plug wires?
I know I need to replace them but you have to buy a whole new coil with the wire built in and I did not get that far.

I took the R/R out of the bike to test it.
I set the meter to diode and connect the Red meter lead to the Red wire on the R/R and the black meter lead to one of the three yellow R/R wires.
And I dont get a voltage reading at all.
That is the first test in test phase C.
The other two test that you get the reading of .50 volts, those tests worked.
But the two 1.5 volts or higher tests I get no reading for?
Any reason I cant test for that or do I need to check that when the bike is idling mabye?

[BassCliff]

Hi,

For what it's worth, it is possible to replace the spark plug wires on these old coils. Carefully chip away the epoxy holding the wires in. Be careful not to damage the spikes at the bottom of the wire holes. Clean the holes, then replace the wires and epoxy them in.


Thank you for your indulgence,

BassCliff

[T mac]

I though of doing that to replace the wore spark plug wires, looks like I will have to do that. I just wanted to ask before doing so. Thanks

[T mac]

New R and R

Replaced R/R and bike runs. May need something elses cause battery wont stay charged it seems.

So now that the bike stays running I started to do the Stator Papers checks. I ran a Ground wire from the R/Rs ground and ran it strait to the battery. On the Test I got to the part were it says to disconnect the stator and run the bike and test for 3 AC powers. But I am worryed about hurting something like my new R/R doing so, so I have not done that yet.
Anyother ways of testing the stator without the bike running? the one test that you test for .5 to 2.0 Ohm's, I get way different reading? So idk.

[tas850g]

check the nylon connector(s) under the tank. I went to get my bike inspected and it would run on 4 cylinders then on 2 cylinders intermittently. I wiggled one of the nylon connectors that must return wires back to the igniter???? maybe and sure enough it would idle poorly then idle smoothly.

Worth a try if you have not done it yet.

[SqDancerLynn1]

disconnecting the stator will not hurt the new regulator

[BassCliff]

Hi,

There are "how to" guides on my site for testing and replacing the stator. Have a look see.


Thank you for your indulgence,

BassCliff