XJ650 seca 1982 ignition fuse issue (12A measured)

Dear everybody,

After a lot of struggles with the bike (holes in the exhaust, holes in the clutch side cover) I finally got around to replacing the fuse box, I now have a fuse box for automotive plug in fuses (no more glass fuses). Unfortunately my ignition fuse (10A) keeps burning out when I put the cycle on run. I've been trying to find a short circuit with the battery out and an ohms meter. The measured Amperage over the fuse is 10.75 to 12.something Amps. So its burning out, but I don't know why..

Any tips regarding finding a short circuit on the ignition fuse circuit?

Best Regards,
Bas

 

i had a similar problem kept blowing fuses. I finally tracked it down to a wire shorting out in the throttle control housing and it was the last place i looked after going through everything. It was my ignition fuse as well so im guessing that will be it.

 

That sounds very interesting as I've been working on that assembly before (couldn't get the starter motor going until I figured out that the steering bar was ground, and the throttle control housing wasn't on the steering bar)

 

are any of the fuses and main fuse mixed up.
i don't know how you measured it but a bare wire to ground will draw more than 12 amps, way more

 

isn't the main fuse a 20A?

 

Yes, and the ignition fuse of 10A is burning out. Been lucky not to have main fuse issues..

 

No we taped them before switching fuse boxes, and before I switched boxes the ignition fuse was burning out as wel (partly the reason of switching fuse boxes). Ik measured the Amps by taking out the fuse and putting te poky ends directly on both sides of the fuse. I thought that was the correct way to meassure actual Amperage but I'm not sure..

 

You need a wiring diagram for you bike, that is step 1.

Step 2 is to have a supply of 10A fuses on hand.

Steps 3 thru whatever are to un-plug all devices on IGNITION circuit, and then plug them in one at a time and note when the fuse blows....now you have isolated which device is the problem, and go from there.

Alternatively you can disconnect each device and see if you have continuity to ground on the "hot" side; the one that does is the problem.

 

i don't know about that Chacal.
if there were 3 plugs (a,b, c) you plugged them in A then B then C popped the fuse, one would think C is the problem. if you did C then B then A popped you would question A.
it's the combination of all 3 that is the problem

 

chacal's advice is probably the best /easiest way to go.
unplug handlebar start/ stop switch
unplug diode block
unplug tci unit
unplug starter solenoid
replace 10a fuse ,
does it blow or not?
if it does then you have a short on the harness.
if it doesn't blow,
plug in handlebar switch
then diode block
then tci
then starter solenoid.
the one that blows the fuse is the culprit, or the wiring from it
stu

 

True, I guess that I should point out that I am assuming that there is only one problem (or, the problem is restricted to only one of the "branch" circuits). But at least you can start narrowing down where the issue might be, which is always the tricky part about these situations.

 

what if a guy were to take out the other fuses and use a 15A fuse in the ignition long enough to verify that the ignition fuse wasn't powering something it's not supposed to.
a lot of fuses could be saved by substituting a small battery charger for the battery, it will let the condition exist long enough to get a handle on it instead of blowing the fuse and being gone. if you use the amp meter with it, you could see if any wiggling/moving wire changes anything

 

Thank you all for the advise! I got a Haynes manual so I'm all set for the diagram. I'll try the plug unplug routine without the fuse, but with a meter to see what the amperage is (will save me some fuses). If I think i found a culprit I will change the order of plugging to see if there are some more pixies flying about.

I'll post an update here somewhere after my exams.

P.s. I just passed for the first of two motorcycle exams required in my country. It's comparable to a motorcycle safety course (braking, figure 8 etc.).