Blowing Ignition fuse
#1
Blowing Ignition fuse
First off, I'm more of a body man then a mechanic. I've got a 99 XLH I got of a buddy and anytime you try to start it, it blows the ignition fuse. I've checked the relay and starter, but found out that the fuse was blown and was told it wouldn't start when I got the bike. I'm getting a copy of an 93-94 manal to help out with running more test to figure out the problem. If anybody out there can help out, Please do. I'd prefer to figure this out with help then go to a dealer.
Thanks,
Cliff
Thanks,
Cliff
#2
#3
#5
RE: Blowing Ignition fuse
Use an OHM meter, and test to see if you have continuity between ground and the fuse holder and on which side of the fuse. Next disconnect your ground cable from your batter and check again. This will let you know whether is grounding through the frame or another ground wire. Electrical diagnosis is some of the hardest troubleshooting to perform but good luck and be patient.
#6
Join Date: Dec 2004
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RE: Blowing Ignition fuse
First question I gotta ask is, what fuse? Did somebody rewire this thing? Or do you mean circuit breaker? Unfortunately the latest Sporty book I have is 1980, but even then there aren't any fuses, only circuit breakers. If it's been rewired and the breaker replaced with a fuse, sorta makes you wonder why, eh? Otherwise the circuit will be similar, no matter the year of the bike, and it doesn't even matter if it's a Big Twin or a Skirtster.
The typical HD ignition circuit comes off the key switch ignition terminal, goes to the ignition circuit breaker, then to the stop (kill) switch on the handlebar, jumps to the start button, then to the starter relay, and through the relay coil to ground. The solenoid and starter motor are not in this circuit.
To troubleshoot this circuit:
Pull the hot lead off the starter solenoid and tape it so it won't accidentally short to ground through the rest of this procedure.
Next, does the breaker trip/fuse blow as soon as it is installed in the circuit, even with the key switch off? Problem might be in the ignition switch itself. Rare, but not unheard of.
If it doesn't trip/blow here, place the kill switch to the off position on the handlebar. Turn the ignition key to the on position. Does the breaker trip/fuse blow? If so, the problem is in the wiring between the key switch and the kill switch. I have also seen circuit breakers go bad and short to ground, sometimes water being the culprit.
If it doesn't trip/blow, turn the key switch back off. Find the starter relay, identify the wire to the hot side of the relay coil, and pull it. This takes the relay out of the circuit. Turn the key switch on, turn the kill switch to the run position. Does the breaker trip/fuse blow? If so, problem is in the jumper wire to the starter button, or in the starter button. Once again, starter switches can crap out and short to ground.
If it doesn't trip/blow, press the starter button. Does it trip/blow? If so. problem is in the wiring, from the starter button to the starter relay. Could still be in the starter button itself, too.
If it doesn't trip/blow, turn the key switch off. Reconnect the relay, turn the ignition switch on and press the starter button. Does it trip/blow? Starter relay faulty.
That's about it. Generally I find some pinched wiring, usually in the handlebar area, sometimes beneath the gas tank. Once in awhile I've found a fried starter relay. Occasionally it'll be someone's poor attempt at rewiring.
Have fun, and hope you get it fixed soon.
The typical HD ignition circuit comes off the key switch ignition terminal, goes to the ignition circuit breaker, then to the stop (kill) switch on the handlebar, jumps to the start button, then to the starter relay, and through the relay coil to ground. The solenoid and starter motor are not in this circuit.
To troubleshoot this circuit:
Pull the hot lead off the starter solenoid and tape it so it won't accidentally short to ground through the rest of this procedure.
Next, does the breaker trip/fuse blow as soon as it is installed in the circuit, even with the key switch off? Problem might be in the ignition switch itself. Rare, but not unheard of.
If it doesn't trip/blow here, place the kill switch to the off position on the handlebar. Turn the ignition key to the on position. Does the breaker trip/fuse blow? If so, the problem is in the wiring between the key switch and the kill switch. I have also seen circuit breakers go bad and short to ground, sometimes water being the culprit.
If it doesn't trip/blow, turn the key switch back off. Find the starter relay, identify the wire to the hot side of the relay coil, and pull it. This takes the relay out of the circuit. Turn the key switch on, turn the kill switch to the run position. Does the breaker trip/fuse blow? If so, problem is in the jumper wire to the starter button, or in the starter button. Once again, starter switches can crap out and short to ground.
If it doesn't trip/blow, press the starter button. Does it trip/blow? If so. problem is in the wiring, from the starter button to the starter relay. Could still be in the starter button itself, too.
If it doesn't trip/blow, turn the key switch off. Reconnect the relay, turn the ignition switch on and press the starter button. Does it trip/blow? Starter relay faulty.
That's about it. Generally I find some pinched wiring, usually in the handlebar area, sometimes beneath the gas tank. Once in awhile I've found a fried starter relay. Occasionally it'll be someone's poor attempt at rewiring.
Have fun, and hope you get it fixed soon.
#7
RE: Blowing Ignition fuse
First off Thanks guys for all your help.
Here a few things I’ve found out since I last posted.
What do you guy think of the coil shorting out. That would cause the fuse to blow.
In 94 Harley started to install fuses on the Sporters, I’m not sure about the other models.
Sincecrazy, Major Thanks for the info, that’s a great way to isolate where to start.
Cliff
Here a few things I’ve found out since I last posted.
What do you guy think of the coil shorting out. That would cause the fuse to blow.
In 94 Harley started to install fuses on the Sporters, I’m not sure about the other models.
Sincecrazy, Major Thanks for the info, that’s a great way to isolate where to start.
Cliff
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#8
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RE: Blowing Ignition fuse
What do you guy think of the coil shorting out. That would cause the fuse to blow.
If you're talking about the starter relay coil shorting, that's one of the things to check. If you're talking about the spark plug coil, then we're talking about 2 completely different circuits. It's fed throught the electronic ignition module.
In 94 Harley started to install fuses on the Sporters, I’m not sure about the other models.
If you're talking about the starter relay coil shorting, that's one of the things to check. If you're talking about the spark plug coil, then we're talking about 2 completely different circuits. It's fed throught the electronic ignition module.
In 94 Harley started to install fuses on the Sporters, I’m not sure about the other models.
#9
RE: Blowing Ignition fuse
pococj,
After rereading your first post a few hundred times, it's starting to make more sense. I hope to have time to try it tonight or tomorrow night. I'm picking up the manual tonight and I want to trace out the wires from the switch to see where the connect.
I see you online, is the second paragragh of the quote, your answer to my first quetion?
Rich and famous? I'd like to find a 99 manual or at leaste a wiring diagram of the bike instead of using an older manual, but that's better then putting on the dark glasses and the red and white cane.
Cliff
After rereading your first post a few hundred times, it's starting to make more sense. I hope to have time to try it tonight or tomorrow night. I'm picking up the manual tonight and I want to trace out the wires from the switch to see where the connect.
I see you online, is the second paragragh of the quote, your answer to my first quetion?
If you're talking about the starter relay coil shorting, that's one of the things to check. If you're talking about the spark plug coil, then we're talking about 2 completely different circuits. It's fed throught the electronic ignition module.
Cliff
#10
Join Date: Dec 2004
Location: Texas! Ya mean there's someplace else?
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RE: Blowing Ignition fuse
CSR, after reading what you wrote about a possible shorted coil I wasn't sure we were talking about the same circuits. The starter relay is the circuit I thought you were talking about. But if you are talking about the spark plug coil, then we be speaking French on one side and Portugese on the other. <G>
At any rate, I hope the manual is of some help. I'm and ex-electrician-now-electronics tech/instrumentation tech. Messing with unknown circuits, with wires going every which way, designed by an over-educated engineer who can't find his zipper to keep from peeing his pants, modified by Bubba "my uncle wuz a wire guy", will drive you insane! I'm proof, though I ain't always sure I qualify as living proof.
At any rate, I hope the manual is of some help. I'm and ex-electrician-now-electronics tech/instrumentation tech. Messing with unknown circuits, with wires going every which way, designed by an over-educated engineer who can't find his zipper to keep from peeing his pants, modified by Bubba "my uncle wuz a wire guy", will drive you insane! I'm proof, though I ain't always sure I qualify as living proof.