Wow, no luck with the electrical on my 03 WR450, help please.

[crashing_sux]

I'm having terrible luck with this thing. When I get the bike it won't hold a charge, after a couple of starts I was back to kicking it. I bought a new battery and life was great for a couple of days, but then I left the ignition button on and killed the battery again. I hooked up a battery tender jr. to the battery and after a day the light was green on the battery tender as if my battery was good, but now my bike won't even attempt to start and stranger yet, the little red light that is supposed to come on when I turn on the ignition (push the on/off button) doesn't come on any more. My bike still starts first kick so it hasn't been a huge issue but I'm a little peeved because I want it to work properly.

Does anyone have any ideas of troubleshooting steps I could take before I resort to taking it to the dealer?

[Motone82]

I am having the same problem. The battery voltage is 12.4. What gives?

[OlaGB]

I'm having terrible luck with this thing. When I get the bike it won't hold a charge, after a couple of starts I was back to kicking it. I bought a new battery and life was great for a couple of days, but then I left the ignition button on and killed the battery again. I hooked up a battery tender jr. to the battery and after a day the light was green on the battery tender as if my battery was good, but now my bike won't even attempt to start and stranger yet, the little red light that is supposed to come on when I turn on the ignition (push the on/off button) doesn't come on any more. My bike still starts first kick so it hasn't been a huge issue but I'm a little peeved because I want it to work properly.

Does anyone have any ideas of troubleshooting steps I could take before I resort to taking it to the dealer?

The first thing to do, is to measure youre battery voltage while ignition is turned off..

Second thing to do, is to measure battery voltage with the motor running, with the lights turned ON.. Measure at idle, and at say, 4000rpm..

Now i would like to see these numbers hehe..

[ETP]

The first thing to do, is to measure youre battery voltage while ignition is turned off..

Second thing to do, is to measure battery voltage with the motor running, with the lights turned ON.. Measure at idle, and at say, 4000rpm..

Now i would like to see these numbers hehe..

Follow this plan. The idea is that, with everything running, the voltage should be over about 12.5 volts. Mine runs at around 13 volts at fast idle with the light on. If it is lower, then either the charging system isn't working, or something is drawing so much power, the charging system can't keep up.

[crashing_sux]

Thanks guys, I'll measure it after the ride today. I figured the fact that the little red light even with the battery tender plugged in and green meant a blown fuse or something (do these bikes even have fuses) but checking the charging system certainly can't hurt.

[WR450F_RDR]

yes they do have fuses, under the seat near the battery, two of them.

[crashing_sux]

It was a fuse, the 10 amp on the right side of the bike. I wonder what could have caused it to fail? I'll carry spares with me in case it happens again, in my experience once a fuse blows it seems like they keep blowing until you figure out what the source of the problem is. Oh well, it's progress, at least my e-start works now.

[Motone82]

mine was the battery. I put a new Yuasa battery in and it fired right up. Now I just have to figure out if something is draining it or if it was just a bad battery. Brand new out of the box on the bench, it was 12.39 volts. Bike running with lights on it was at about 14.45. Is this normal? Thanks

[ETP]

mine was the battery. I put a new Yuasa battery in and it fired right up. Now I just have to figure out if something is draining it or if it was just a bad battery. Brand new out of the box on the bench, it was 12.39 volts. Bike running with lights on it was at about 14.45. Is this normal? Thanks

12.39 volts out of the box sounds about right for a new battery that hasn't been charged in a while. Bike running with lights on at 14.45 sounds a little high for charging, but not too bad. If it charges above 15 volts with the lights off, I'd be suspicious of the voltage regulator circuit.

Maybe someone here knows what voltage is too high for charging a 12 volt battery?

[Motone82]

Thanks ETP. I was a little concerned. I dont know if that is what killed the other battery or not. It was supposedly brand new and lasted one day. If I ran the volt meter across it, it said 0.0. I dont want to spend $95 bucks everytime I ride it.

[crashing_sux]

So, while I have the attention of a few electrical gurus, is there an easy way to get to switched power on my bike? I have hot grips wired into DC and when I accidentally leave them on they'll drain the battery.

My thoughts on solving the problem were:

1: Replace the high/off/low toggle switch with a lighted switch to keep me from forgetting them.

2: Wire them into AC (the yellow wire going to the headlight switch) but will that lower the available power to my headlight more than wiring it DC?

3: Find switched power DC that is only on when the on/off switch is depressed (the one with the little red light).

Any better ideas?

[450high]

i wired mine up to the on button.I can't remember how, it's been a while but when i turn off the ignition button with the light it kills the grips.Took a while to figure out but it's possible.Post back if you need me to pull the headlight and check witch wires,

[ETP]

Thanks ETP. I was a little concerned. I dont know if that is what killed the other battery or not. It was supposedly brand new and lasted one day. If I ran the volt meter across it, it said 0.0. I dont want to spend $95 bucks everytime I ride it.

Make sure you're not overcharging that battery. Check the charge voltage with the lights off and see if you can find out what the max charge voltage should be.

[ETP]

So, while I have the attention of a few electrical gurus, is there an easy way to get to switched power on my bike? I have hot grips wired into DC and when I accidentally leave them on they'll drain the battery.

My thoughts on solving the problem were:

1: Replace the high/off/low toggle switch with a lighted switch to keep me from forgetting them.

2: Wire them into AC (the yellow wire going to the headlight switch) but will that lower the available power to my headlight more than wiring it DC?

3: Find switched power DC that is only on when the on/off switch is depressed (the one with the little red light).

Any better ideas?

Don't have any experience with those hot grips, but it seems like a good idea to wire them to the AC circuit. I think the AC can handle about 20 watts more before it starts to bog down.

These electrical systems were designed for light weight, so there isn't much available power for accessories. Hook it up and see if the AC voltage holds up while running.

[WR450F_RDR]

Look at the electrical schematic. I am using a DC circuit on my home brew dual sport kit to operate horn and turn signals. there is a DC circuit that is only hot when the ignition switch is on,tap into it. The little red light helps to remember to turn things off.

[crashing_sux]

Do you remember what color the wire is? I looked at the electrical diagram but reading those isn't my strong suit.