[dmr]

Hello, newbie here. Just found this forum and have done a search but haven't come across this question.
I am trying to trace a short that keeps killing the battery on a 2002 350FE while it is turned off. I have downloaded the. wiring diagram and have been trying to trace the circuits, starting with the red (+) side. Red wire goes from battery positive to the ignition key with branches to the rectifier (checks OK) and to the gauge console -CPU. I measure a short to ground on the harness side of the ignition switch connector until I disconnect the 14 pin connector to the gauge console. This would seem to indicate to me that the short is somewhere in the wiring from the connector to the gauges or internally in the gauge cluster. Has anyone else come across this?. I would hate to replace the gauge cluster if my troubleshooting logic is faulty. Connectors and wiring all look very good with no corrosion or chafing. Just not sure if there should be continuity to ground on the red wire with that connector plugged in.
Thanks for any advice or ideas.
Dave

 

[jkhuntin]

Welcome to the forums. Someone will be along shortly to help you.

 

[TRX2fiveO]

Check your grounds and clean the top of the battery with battery cleaner invest in some die-electric greas for all the connection points in the harness,

 

[Helmut]

Welcome to the forums.

 

[Green]

How exactly are you measuring a short? What I mean is, what is the resistance or voltage drop? Could there be a component that is not disconnected with the key switch that is consuming power?

I'm an electrical engineer, and I'll try to help, but I need a little more info. Can you post your wiring diagram?

 

[Helmut]

How exactly are you measuring a short? What I mean is, what is the resistance or voltage drop? Could there be a component that is not disconnected with the key switch that is consuming power?

I'm an electrical engineer, and I'll try to help, but I need a little more info. Can you post your wiring diagram?

The display probably pulls a small amount of power, with the key off, because of the memory.

 

[Pain]

It may pull power, but there's non-volitile memory now like that in USB sticks that don't require power to maintain the data. Not sure it was in wide use in 2002 though, but it was available then...it may have been expensive though.

 

[Helmut]

It may pull power, but there's non-volitile memory now like that in USB sticks that don't require power to maintain the data. Not sure it was in wide use in 2002 though, but it was available then...it may have been expensive though.

I bet it does have that, because if it didn't, the mileage would probably reset to zero if you unplugged the display. I don't know much about the displays, I've never tried to work on one.

 

[shadetree]

Hello, newbie here. Just found this forum and have done a search but haven't come across this question.
I am trying to trace a short that keeps killing the battery on a 2002 350FE while it is turned off. I have downloaded the. wiring diagram and have been trying to trace the circuits, starting with the red (+) side. Red wire goes from battery positive to the ignition key with branches to the rectifier (checks OK) and to the gauge console -CPU. I measure a short to ground on the harness side of the ignition switch connector until I disconnect the 14 pin connector to the gauge console. This would seem to indicate to me that the short is somewhere in the wiring from the connector to the gauges or internally in the gauge cluster. Has anyone else come across this?. I would hate to replace the gauge cluster if my troubleshooting logic is faulty. Connectors and wiring all look very good with no corrosion or chafing. Just not sure if there should be continuity to ground on the red wire with that connector plugged in.
Thanks for any advice or ideas.
Dave

when your getting a power reading from your key switch..which side are you getting a reading ?..comming into ?..or going out ?..you will always get a power reading comming into the ket switch..even if the ket is off..the red wire is always hot..when you switch the key on..all this does is complete the circuit to allow the power to go back out...into the wire harness..lights..so forth. as for your display..i'm almost positive it will always have a low voltage going into it..so it keeps the memory in your hours/miles...gotta ask..but...what makes you think your battery is draining ??..because you charge it..and it won't hold a charge ?...this does not mean you have a short or what ever in your bike. now..if you were blowing fuses left and right..then yeah..i would say you got a short in your wire harness...if you charge your battery...and after it sits for a bit..and it won't crank your bike..i would first check your stator..reg/rec..these are what keeps your battery charged. your battery could have a bad cell in it ??.also..i can not stress this enough..and this tip will save you alot of trouble...just because a battery shows 12v's..or more..does not mean it has the power to crank a engine..it's not the voltage that cranks a engine..it's the cranking amps !!!..you can have 12v all day long..and it still won't turn an engine.

 

[dmr]

Thanks for all the replies. I appreciate your trying to help. This site is a wonderful resource. Can't figure out how to post the wiring diagram. I got it from the schematics/manual help section of this site. Thanks to Helmut for posting it.
Just to clarify: a freshly charged battery (13 V) goes stone dead in a couple of days while sitting turned off so there must be a short somewhere pulling power while the key is off. My logic was to disconnect the battery and trace the red (hot) side wiring up to the key switch, thinking that a short would have to be before the switch. I have been checking resistance to ground on the frame and keep getting continuity on the battery side of the key switch from red to ground. Here's whats throwing me for a loop. The red wire T's off before the key switch and goes direct to the CPU in the gauge cluster so it is not switched by the key. There is something else strange going on with my continuity readings which I haven't come across before. My meter only shows continuity to ground from the red wire when the meter's + probe is touched to ground, but not in reverse when the - probe is grounded. I'm thinking this must have something to do with diodes in the system only allowing current to flow in one direction through the meter but I have never come across uni-directional continuity readings before.. I think what I'll do next is hook the battery back up and measure the current draw with the key off while disconnecting the plugs one at a time to see if that will isolate it.
Anyways, thanks for the advice so far.
Dave

 

[Green]

Thanks for all the replies. I appreciate your trying to help. This site is a wonderful resource. Can't figure out how to post the wiring diagram. I got it from the schematics/manual help section of this site. Thanks to Helmut for posting it.
Just to clarify: a freshly charged battery (13 V) goes stone dead in a couple of days while sitting turned off so there must be a short somewhere pulling power while the key is off.

Not likely...a short is extremely low (or no) resistance in an electrical circuit. A short will usually blow a fuse, damage a component, or burn a wire if not fused.

My logic was to disconnect the battery and trace the red (hot) side wiring up to the key switch, thinking that a short would have to be before the switch. I have been checking resistance to ground on the frame and keep getting continuity on the battery side of the key switch from red to ground. Here's whats throwing me for a loop. The red wire T's off before the key switch and goes direct to the CPU in the gauge cluster so it is not switched by the key.

The gauge cluster is a load on your battery...it will consume power and will eventually drain your battery. Under normal circumstances, your battery will normally support this load for a long time...I would think it would be less than 100 mA.

There is something else strange going on with my continuity readings which I haven't come across before. My meter only shows continuity to ground from the red wire when the meter's + probe is touched to ground, but not in reverse when the - probe is grounded. I'm thinking this must have something to do with diodes in the system only allowing current to flow in one direction through the meter but I have never come across uni-directional continuity readings before..

You are correct. There is at least one diode in the circuit you are testing. Switch your meter to Ohms and measure resistance rather than continuity. Generally speaking, the continuity checker on a DMM is synonymous with "diode checker".

I think what I'll do next is hook the battery back up and measure the current draw with the key off while disconnecting the plugs one at a time to see if that will isolate it.
Anyways, thanks for the advice so far.
Dave

My bet is that your battery is toast. Remove it, charge it overnight, and while it's on your bench, put a small load on it. By small, I mean try to find something 150 mA or less...find yourself a small LED light and wire it across the battery. See how long it takes to drain the battery. You can find cheap 12V LED accent lights at any truck stop.

 

[dmr]

Hello again.
Plugged all the connectors back in, except left the gauge cluster isolated.
Checked for current flow and found a draw of 110 milliamps with the key off.
Unplugged the regulator/rectifier and find no current flow now.
Would this indicate a partial short to ground through the regulator? I took it off and it was stuck to the frame at one small spot where there was what appeared to be either black charred paint or possibly some sort of heat sink compound adhering it to the frame.
I had previously checked the regulator as per the manual and have not been blowing lights so I haven't suspected it.
Several posters have suggested a weak battery not being able to maintain but I have been using 2 new fresh fully charged batteries that go flat in a couple of days.
I also realize I am guilty of not mentioning that when I first started having trouble I found the main 30 A fuse blown. Replaced it and it hasn't blown again but I can't remember if I have run the bike since. I only use it in the winter for plowing snow and normally it sits all summer without killing the battery.
Thoughts on that regulator?
Thanks

 

[Pain]

point me to the wiring diagram and I'll look at it and see what's up.

My opinion is there should be no current flow through the regulator with the machine off.

Just for information and since you have the means, unplug the regulator and measure the current flow with the gauge cluster plugged in. I am going to guess it's near zero.

 

[dmr]

Pain, thank you for your offer.
I got the wiring diagram from the Honda ATV Schematics/Manual Help forum on this site. Page 2, about halfway down - Honda Rancher 350 Repair Manual, last post 06-14-2010. Page 22.6 wiring diagram for Canada TE/FE 00-02.
I measured the current draw with the gauge cluster plugged in and the regulator unplugged - initial draw 1.8 milliamp for approximately 1/2 second, then stabilizes at 0.6 milliamp. That seems like a reasonable level.
As soon as I plug the regulator back in it jumps to 100 milliamps.
Sure seems like the regulator is shorting to ground somehow but I hope to confirm that because I imagine a new regulator will be at least $150.
Thanks,
Dave

 

[Pain]

I think you're right. Like Green said, it's not really a short, but for all intents and purposes you could say it's a short....it's more accurately a leak or even a high-resistance short....but 100ma seems excessive to me when off but I have never tested one myself so I can't say for sure that is your problem.

BTW, to post a link, just copy the entire URL from the address window in your browser and just paste it into the post. Like below, except I replaced the colon and the dot with the spelled out words so you could see it. Below that text I paste the unedited link so you can see how it will appear:

http colon //www.hondaatvforums.net/forums/honda-atv-schematics-manual-help/3010-honda-rancher-350-repair-manual dot html

http://www.hondaatvforums.net/forum...elp/3010-honda-rancher-350-repair-manual.html

 

[dmr]

Thanks all, and especially Pain for your help.
New voltage regulator finally came in, just installed it and solved the problem! I hadn't originally suspected the voltage regulator because I hadn't been blowing any lights. As soon as I had the new regulator I could see that the continuity readings were different (old one had continuity to ground from all 5 pins, new one shows no continuity) and no current draw with the new one in the system.
Interestingly, although I found lots of info on how to test a regulator for voltage when running and how to test the harness I never found any info on how to test a regulator off the bike - i.e. correct pin readings.
What I learned which might help someone else:
1. Correct wiring diagram is a must (thanks to this site!)
2. Find and identify all the connectors and disconnect. (I started unravelling the harness first thinking a wire must have rubbed through and wasted a lot of time).
3. There are a number of diodes in the system and on my old analog multimeter I would get different ohm readings depending on whether I grounded the red or black probe of the meter. Very confusing.
4.Hook up ammeter in series with battery and start plugging connectors back in and BINGO that will tell you which section of the harness has the short (actually more of a leak in this case) and take it from there.
Dave

 

[Pain]

Good information, thanks for posting back.

 

[Matfire17]

if you were blowing fuses left and right..then yeah..i would say you got a short in your wire harness.





---My bike just recently purchased TRX350tm '06 is blowing the 15amp fuse which amongst other things powers the display etc upon start-up or attempting to - sorry for such a newbie question but what should i look for, frayed wiring loose connections??? any suggestions on a likely spot?