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Jump started Harley using car and now it won't start.

12721 Views 21 Replies 11 Participants Last post by  Unkle Krusty
Replaced the coil, voltage regulator, and ignition module and still won't start
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Check all your fuses and cable connections.
I've read a couple posts about people using cars to jumpstart their motorcycle s and that causing electrical problems but don't know what else to replace.
Was the car running? If not, there is usually no damage. If yes, you could have killed the battery pretty fast.
What year and model?
Yes the car was running. Took awhile to start the motorcycle and that's the last time it ran.
Seems like it's not getting spark. Don't think it's the battery had the battery on a battery tender after the incident but that didn't help.

For one thing, you need to check the voltage of your battery. If it's between about 12.50 and up and your battery connections are clean, then you should have what is needed to keep the juice flowing in that area. If the battery is down to much less, then it might not be good. Possible battery charger input can bring it back up.

Replaced the coil, voltage regulator, and ignition module and still won't start
Was it starting just fine before replacing all this stuff? The coil or ignition module could be bad. Are you sure it's an electrical issue? Try spraying some carb cleaner or very small amount of starter fluid in the air breather. If it fires or tries to then you have a fuel issue. If it doesn't then you'll have to get your voltage meter out and trace where you lose spark. There are threads(stickys) that have info in that area or there's a thread about it. I can't remember which. But it's in the repair forum. Or maybe someone might feel like repeating it here yet again.
may be its battery is dead when you did jump started it, or its fuse burnt out
It was a really cold morning and it took awhile for it to finally start but that's the last time it ran. Replaced the ignition module, coil, and voltage regulator along with the plugs trying to narrow down the problem.
Took the battery to Auto zone to have it tested and they said it was good.
For not much money you should get a volt meter, and monitor the battery. It should maintain around 12.75 volts. If it sits at about 12.35 to 12.55, it is getting tired.
If it drops to 12.25 it is 50% discharged and needs charging. Nothing more than 2 amps on an automatic charger. When the engine is running the volts should rise to 14.5 max.
By monitoring the battery, you get a much better idea as to its condition.

The multi meter will have a small battery inside that needs to be changed maybe once per year.

Starting a bike with the car engine running is a bad idea, good way to fry the electronics. Always jump bike with vehicle engine not running using car battery only. You must have fried something else. What year and model?
What do you mean "won't start"?

Does it turn over at all?

If there are no lights, then you have a dead battery or open circuit (blown fuse).

If the bike lights up, but the "start button" does nothing, then you have:
A. An electrical problem - melted/cut wire/connector or blown computer.
B. A mechanical problem - Failed starter, ect.

Stop throwing parts at it and start troubleshooting logically...we can help you, but we need details...can you post a video of you attempting to start it?
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good work 450 zuki

Easy to mess up, Gotta be able to be crankt over b4 it can start, I wondered 'Is it cranking over? gas valve on?
if everything else came onbut would not crank, seems it would be a strange coincidense starter switch or solenoid
went bad. I have personally jumped a 91 Harley sporty and wide glide to a running pick-up truck to charge the
bike's battery.

Pretty sure H-D says not to have vehicle running. why?
who freaking knows but u have to have a few more volts to push current into bike battery, or u end up with a back voltage
that will keep bike battery from charging, so u charge bike battery from a running vehicle. of course hooking leads backwards
will most likely blow the R/R or maybe puter too .

Also have had excellent luck with battery tenders, bikes start in less than 1/2 the time with them than without.
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may be its battery is dead when you did jump started it, or its fuse burnt out

My wide glide's has a battery charging fuse, accessories fuse and a main fuse. if battery charging fuse is
blackened, very likely like 99% a short either a bad wire somewhere or R/R crapped out causing current
to flow back to stator . If it is clear and u see the melted link maybe fuse opend due to taking too long for battery
to charge at high current. same as a 20 amp house fuse or circuit breaker. pull rated current thru it too long and it
will open up. if it is blackened, there was a sudden surge of lotsa current.

As I said b4 u gotta have a bit more volts from charging system than battery to force current to te battery.

if u had a bike with a 6 volt system and jumped to a 12 volt with car not running good chance of burning out things.

harley does not want u to jump to running car because they don't want to be financially responsible for fixing it
but when u really thing about it, it is NO different than charging with a car. The vehicles alternator puts out more
current, yes it does but the bike battery also has an internal resistance which also determines how much current can
go through it and as long as you have around 13 .5 to 14 or 15 volts. you should have NO trouble.
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Pretty sure H-D says not to have vehicle running. why?
Why is because the alternator in a large vehicle, like a truck or auto, is designed to charge a battery of 50-100Ah, while the battery in your bike is between 10 and 20Ah. Charge current should be about 1/10 to 1/5 the Ah rating, not much more. Your running truck can easily put more than 10-20A into your little battery, which will damage the plates. Jump starting should be just that - starting, not charging. Once your bike is running, it should be able to keep running on the output of the charging system.
Hello WinrSol.

I may have lucked out when I charged a bike battery from a running pick-up truck but the battery was not down by much,
and Maybe the truck's alternators voltage regulator saw not much of a load and the voltage regulator allowed the alternator
to put out less power?
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