Diagnosing Electrical Short - Assistance Needed

'05 R3 - Jars, K&N's, TB etc.

I used to blow 30A fuse once a year but lately it has gotten much worse and I lost tail light fuse and blew the license plate bulb and idle is crap so I have no choice but to resolve this. Fuse Melted last go round so I spliced in an in-line 30A holder.

I unhooked after market LED's and Steble Horn.

TESTING Update:
1. 12.5V Across battery, unhooked negative post
2. tested between ground cable & negative post -
2.1 All fuses in - meter reads 10.81 (not right)
2.2 10A fuse #3 out - meter drops to 9.61 (two electrical issues?) Ignition switch issue?
2.3 All other fuses seem fine.

I have no accessary plugs, heated grips etc - the dealer did work on the throttle controls replacing a cable but I don't see a pinched wire in there.

I could have sworn bike ran better with fuse 4 ( 15A Alarm, diagnostic connector, indicators, brake lights) out so I was surprised to not see any voltage changes with that fuse removed. Hope thats a side effect and not a seperate issue.

I am now going through all the cabling, removing old tape, cleaning etc. and am appliyng dielectric grease and retaping or shrink wrapping those that look fine.

I'm following an electrical short self-help guide but any pointers are appreciated.

Ordered new R/R, Battery. Never did do ignition switch mod.

tribal said:

'05 R3 - Jars, K&N's, TB etc.

I used to blow 30A fuse once a year but lately it has gotten much worse and I lost tail light fuse and blew the license plate bulb and idle is crap so I have no choice but to resolve this. Fuse Melted last go round so I spliced in an in-line 30A holder.

I unhooked after market LED's and Steble Horn.

TESTING Update:
1. 12.5V Across battery, unhooked negative post
2. tested between ground cable & negative post -
2.1 All fuses in - meter reads 10.81 (not right)
2.2 10A fuse #3 out - meter drops to 9.61 (two electrical issues?) Ignition switch issue?
2.3 All other fuses seem fine.

I have no accessary plugs, heated grips etc - the dealer did work on the throttle controls replacing a cable but I don't see a pinched wire in there.

I could have sworn bike ran better with fuse 4 ( 15A Alarm, diagnostic connector, indicators, brake lights) out so I was surprised to not see any voltage changes with that fuse removed. Hope thats a side effect and not a seperate issue.

I am now going through all the cabling, removing old tape, cleaning etc. and am appliyng dielectric grease and retaping or shrink wrapping those that look fine.

I'm following an electrical short self-help guide but any pointers are appreciated.

Ordered new R/R, Battery. Never did do ignition switch mod.

Click to expand...

Sorry dont know your electrical background and you maybe tried these..

You may know .. up-rating fuse values can cause Fire in the harness,
as you know fuses blow because of heat in the circuit so the cable is the same temp as the melting fuse..just saying.

If your a voltage ground check reads 10.8 v your have a dead short somewhere
and you should be able to feel the harness heat at some point or even see smoke or heat damage.

Check inside cable connections of units such as tail lamps for corrossion also for chaffing where harness or cable goes thru' metal via hole.

Check the parts of the harness that bends or pulls tight like around the steering head some cables can chafe or break.

Only other thing I can think of is previous owners may have connected things into the harness by splicing un professionally or just cut cables to remove before selling.

It seems you have a dead short circuit somewhere maybe..

Just suggestions..hope it helps.

Thanks,

My electrical skills are zippo - I'm forcing myself to go through this excercise to learn.

As I am red/green color blind (challenged?), I have tended to avoid that field of study.

There is definetly a short - finding it has proven to be challenging.

I will be unplugging the front blinkers and headlights next to rule those wires out and checking all connections under the tank.

How do I check the key switch?

Another thing - when I turn on the ignition the speedo needle does the self test but the tachometer needle sits there until the bike starts - is this normal?

No not normal ,they should both sweep at the same time.

I would think you have a ground leakage some where it may be the Techo,keep looking till you find it, There is a flow of amps going in the wrong direction back down the system.

tribal said:

Another thing - when I turn on the ignition the speedo needle does the self test but the tachometer needle sits there until the bike starts - is this normal?

Click to expand...

No it's not. hearing this i'm surprised that the tach works.

Diagnosing electrical problems is IMO one of the hardest trouble shooting issues there is. Fortunately the actual problem is usually rather simple, finding it is whats tough.

You need a way to measure how much current is being drained from the battery. The best way is with a quality meter with a clamp on type amp meter. This clamps on around a wire and measures the current running through it.

Start with the key off and the clamp sensor on either the negative or the positive wire from the battery, it really doesn't matter because current just makes a loop from one side to the other.

Key off the current should be zero or very near that. If it's not there is a problem. Your tach not sweeping is a problem.

When you turn on the key you will get a current reading. I don't know what a good base line reading should be. Sorry but I don't have this issue so I haven't had to invest in the tooling to investigate this. Hopefully someone will add to this.

Connect a tender or low amp battery charger to the bike. This could take some time.

Even without this information you can still get clues to what he problem could be. Pull the head light fuse this should be the biggest current draw. I would next remove the little light blubs in the head lights. Remove the fuse for the tail lights.

After the head lights were there any big current drops?

Continue to remove non-essential fuses and check for large changes in current.

Couple of other things. Are there any non-stock wire connected to the battery? If so check these first.

It's hard for me to give good advise over the internet. I'm more of a hands on guy. But I'll try. Good luck.

lifted tank and unplugged every plug I could see and still get 9.61v across negative terminal. Cleaned, greased and plugged everything back in.

Pulled all relays on left and right side, greased, and reseated - all seemed fine.

Will look at key switch plug and headlights next and try to trace Tachometer cable back to harness plug...

Turned key on - getting 12.43 reading.

Also, there are two cables coming off positive battery terminal. The large main one and a smaller one that runs into the wiring harness. When I diconnect the small one the short goes away (no power, no short).

Thx all.

My bet is in the switch. Not only is the wiring design less than adequate with all that headlight power going through the switch but also when I re-did mine, I had never seen such a shoddy example of soldering on all the lugs on the bottom side of the switch. There were cold solder joints and too much solder in places.

indications are that I have multiple issues. Here is an update:

disconnected front lights - no change
disconnected key switch - no change

THEN, I unplugged the regulator and number dropped to .05. Plugged in a new Reg and it went back up to 9.6 with fuse #3 out (10.8 with all fuses in).

Fired bike up and it actually sounded good and was idling much better.
switched meter to more sensitive setting - now 053.

Pulled fuse #4 and it drops to 021.

It still looks like there is a short somewhere but ****ed if I can find it.

I will be hard wiring R/R to battery with new kit.

Also waiting for Eastern Beaver to send me the headlight kit H4 Dual Relay Kit for Rocket III
Item #: H4DRK-R3

Just a thought... recently in wet weather I noticed A lot of steam rising from the exhaust cat area I have eliminator no cat but I removed the right side panel and the ECU was covered in condensation.. the same would be in the left side where all the other multi plugs are parked.. have you checked behind these panels?