Battery Drain Teaser
Thread Starter
|
Cruiser
Joined: Aug 2007
Posts: 131
Likes: 0
From:
Battery Drain Teaser
Here's my brain teaser.......
I ride a 1986 FLHTC, 58500 miles.
My recurring problem is this.
The battery "appears" to discharge, sometimes overnight and sometimes in under 6 hours.
I say "appears" to drain, because I am not convinced it has.
The other day, when leaving work, the bike would not start, very slow turning over, to the point that it stopped cranking. I tried to push start it, (3 times) no luck. Let it sit for 5 minutes, hit the starter once more and it spun over like there had never been a problem.
Put it on the trickle charger over night, and the next morning, no problems at all. Yesterday, went to lunch and it struggled a little, but started. Started it 15 minutes later ( went back to work) no problems. After work, would not start period.
This has been a developing pattern....
This is what I have done:
New Starter
New Battery
New Solenoid
New cables
Extra ground cables (less than 0.1 ohm loss)
32 amp 3 phase charging system
new circuit breakers
new coil and HT leads
Comp Releases
New handlebar switches
The only thing that even comes to mind right now, is this:
Could the ignition system be the weak link? Could it be causing
a. Drain
b. higher impedance
or could it be the Ignition switch?
I have check and triple checked every connection I can think of and everything is good.
Any input wold be greatly appreciated.
I ride a 1986 FLHTC, 58500 miles.
My recurring problem is this.
The battery "appears" to discharge, sometimes overnight and sometimes in under 6 hours.
I say "appears" to drain, because I am not convinced it has.
The other day, when leaving work, the bike would not start, very slow turning over, to the point that it stopped cranking. I tried to push start it, (3 times) no luck. Let it sit for 5 minutes, hit the starter once more and it spun over like there had never been a problem.
Put it on the trickle charger over night, and the next morning, no problems at all. Yesterday, went to lunch and it struggled a little, but started. Started it 15 minutes later ( went back to work) no problems. After work, would not start period.
This has been a developing pattern....
This is what I have done:
New Starter
New Battery
New Solenoid
New cables
Extra ground cables (less than 0.1 ohm loss)
32 amp 3 phase charging system
new circuit breakers
new coil and HT leads
Comp Releases
New handlebar switches
The only thing that even comes to mind right now, is this:
Could the ignition system be the weak link? Could it be causing
a. Drain
b. higher impedance
or could it be the Ignition switch?
I have check and triple checked every connection I can think of and everything is good.
Any input wold be greatly appreciated.
HDF Community Team
Joined: Dec 2005
Posts: 5,378
Likes: 2,574
From: NC USA
The power to the starter relay comes from the ignition switch, to (and thru) the starter relay then back to the acc breaker. At the starter relay, it switches from "starter engage" to "acc power" via the 5-pole relay. The ign position only activates the coil/module seperately from the acc circuit.
Long and short - those ign switches get tired and the power to the relay for the starter, as well as all accessories, is compromised. And it's my guess you're simply not getting enough amperage all the time to activate the starter solenoid because of it.
I didn't see mention that you'd changed the starter relay... so if all the other accessories (turn signals, brake lights, volt guage) seem to be up to snuff and the volt guage doesn't jump all over when braking or turn signals are activated, try replacing the starter relay. It may be weak on the "87" terminal, but ok on the "87a" terminal.
Long and short - those ign switches get tired and the power to the relay for the starter, as well as all accessories, is compromised. And it's my guess you're simply not getting enough amperage all the time to activate the starter solenoid because of it.
I didn't see mention that you'd changed the starter relay... so if all the other accessories (turn signals, brake lights, volt guage) seem to be up to snuff and the volt guage doesn't jump all over when braking or turn signals are activated, try replacing the starter relay. It may be weak on the "87" terminal, but ok on the "87a" terminal.
Tourer
Joined: Aug 2006
Posts: 282
Likes: 7
From: Southern MD
You could check the current with an ammeter (should be zero milliamps) while the ignition is off. You also need to check that the battery is charging while it is running.
If you don't have an ammeter, pull the negative cable off the battery and measure voltage between the neg battery terminal and the negative cable. If it reads any voltage you have some current flowing, which could drain your battery. You will have to look for short circuits buy disconnecting wires until the voltage reads zero.
Buy some type of voltage indicator to install on the bike, connected to the +12volt ignition circuit. If your charging system is working the indicator will show a higher voltage running than when not running. If not you have a bad electrical connection or failed component.
One of your new items could be defective. You might have to measure the cranking voltage at the battery (shouldn't drop below about 9 volts). Check the cranking current. You need to find someone with a clamp on ammeter and determine if amps exceeds battery or starter ratings.
Take rings off fingers and feel the starter cables for heat. Warm is OK but smoking, burn your finger hot, is bad and could indicate a loose connection.
Keep us posted.
If you don't have an ammeter, pull the negative cable off the battery and measure voltage between the neg battery terminal and the negative cable. If it reads any voltage you have some current flowing, which could drain your battery. You will have to look for short circuits buy disconnecting wires until the voltage reads zero.
Buy some type of voltage indicator to install on the bike, connected to the +12volt ignition circuit. If your charging system is working the indicator will show a higher voltage running than when not running. If not you have a bad electrical connection or failed component.
One of your new items could be defective. You might have to measure the cranking voltage at the battery (shouldn't drop below about 9 volts). Check the cranking current. You need to find someone with a clamp on ammeter and determine if amps exceeds battery or starter ratings.
Take rings off fingers and feel the starter cables for heat. Warm is OK but smoking, burn your finger hot, is bad and could indicate a loose connection.
Keep us posted.
Thread Starter
|
Cruiser
Joined: Aug 2007
Posts: 131
Likes: 0
From:
Thanks for the input.
Let me add....
I have replaced the Relay., I have even replaced the main power cable that feeds it.
Whenever I have checked the battery drain, I get approx 0.5 amp. (The bike does have an Analog clock and Radio/Cass player)
The Voltage meter in the fairing does show a positive voltage (13 - 14 volts) when bike is running, although at idle, with brake lights on it will drop to 11v. Indicator lights do cause the voltage to drop, but never below 12v while riding.
Battery cables do not get "hot" while cranking.
This really is one of those intermittent problems, I can let the bike sit for days and it is fine. Other times, in just a couple of hours, it wont have enough power to start. (it will turn over but won't fire)
The dash volt meter (new moco) will drop down to 8-9 volts on crank when it behaves itself. After sucking on the tender last night, it fired right up.
Let me add....
I have replaced the Relay., I have even replaced the main power cable that feeds it.
Whenever I have checked the battery drain, I get approx 0.5 amp. (The bike does have an Analog clock and Radio/Cass player)
The Voltage meter in the fairing does show a positive voltage (13 - 14 volts) when bike is running, although at idle, with brake lights on it will drop to 11v. Indicator lights do cause the voltage to drop, but never below 12v while riding.
Battery cables do not get "hot" while cranking.
This really is one of those intermittent problems, I can let the bike sit for days and it is fine. Other times, in just a couple of hours, it wont have enough power to start. (it will turn over but won't fire)
The dash volt meter (new moco) will drop down to 8-9 volts on crank when it behaves itself. After sucking on the tender last night, it fired right up.
Tourer
Joined: May 2008
Posts: 442
Likes: 0
From: High Desert of So Cal
Had a similar problem once and it turned out to be the stator. By all appearances it seemed to be charging (13-14 volts) however there wasn't enough current to get the job done. Check out all your switches and then check out your charging system with a meter. Don't rely on a dash gauge. I think if you do a search there is a list of steps to follow for troubleshooting the charging system here.
Tourer
Joined: Aug 2006
Posts: 282
Likes: 7
From: Southern MD
I think your problem is the .5 amp drain. Clocks and such usually draw around 10-20 milliamps each when ignition is off, not 500 milliamps. Start disconnecting things until that current draw drops way down.
Elite HDF Member
Joined: Sep 2007
Posts: 4,468
Likes: 12
From: Bluffton, South Carolina
Get a pushbutton end cap for your solenoid. The next time it is acting up when you try to start it look at the lights, do they dim??? Then push the button on the solenoid , if it turns over then the problem is in the impulse side of the srarting circuit. Hope this helps.
P.s. Gell batteries can set on the shelf for a while before they are sold, check the voltage with a meter as you are cranking it.
P.s. Gell batteries can set on the shelf for a while before they are sold, check the voltage with a meter as you are cranking it.
Trending Topics
HDF Community Team
Joined: Dec 2005
Posts: 5,378
Likes: 2,574
From: NC USA
I don't know where my mind was at on my first response (post #2) and all I said was correct, but clearly doesn't apply to your deal, Ozzie.
At any rate... the "acceptable" total current draw is 40 milliamperes (.04 amp) or less and the regulator alone should only be 3 milliamperes. The resistance measured across any of the 3 stator wires should not exceed .3 ohms and of course 0 ohms from any stator output pin to ground. You have .5 amp total amp draw and that is enough to run one down rather quickly, yet it's an intermittent situation so you have a real puzzle for sure.
AGM batterys can do some weird things. I've had a couple that would hold a great surface charge for months, yet had no reserve at all. And one that had all kinds of reserve but wouldn't charge above 12.8 and one that acted about like yours seems to be. And I've seen a few ocassions where the regulator was not rectifying the AC and throwing out a really ragged DC giving a false voltage reading on a needle type volt guage and not properly charging the battery.
You've given a lot of good info but if I may ask, was this a problem before all the charging/starting parts replacements and how old is the battery now?
At any rate... the "acceptable" total current draw is 40 milliamperes (.04 amp) or less and the regulator alone should only be 3 milliamperes. The resistance measured across any of the 3 stator wires should not exceed .3 ohms and of course 0 ohms from any stator output pin to ground. You have .5 amp total amp draw and that is enough to run one down rather quickly, yet it's an intermittent situation so you have a real puzzle for sure.
AGM batterys can do some weird things. I've had a couple that would hold a great surface charge for months, yet had no reserve at all. And one that had all kinds of reserve but wouldn't charge above 12.8 and one that acted about like yours seems to be. And I've seen a few ocassions where the regulator was not rectifying the AC and throwing out a really ragged DC giving a false voltage reading on a needle type volt guage and not properly charging the battery.
You've given a lot of good info but if I may ask, was this a problem before all the charging/starting parts replacements and how old is the battery now?
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,195
Likes: 3,085
From: NW AR
Find the half amp drain. As Rob says, start disconnecting stuff. Pull the faring off, go to the bank of breakers and start disconnecting one end of each one until the half amp reading dissapears at the battery. Then start following that circuit. Also try disconnecting the line from the regulator, which goes to the main breaker, if I recall, under the seat. If you have every breaker under the faring disconnected and still have that half amp draw, then pull disconnect the main breaker under the seat. If it still draws, then the only thing left is the starter solenoid.
I'm going to take a SWAG and say the clock/radio keep alive.
Something should be kinda warm to the touch too.
I'm going to take a SWAG and say the clock/radio keep alive.
Something should be kinda warm to the touch too.
Thread Starter
|
Cruiser
Joined: Aug 2007
Posts: 131
Likes: 0
From:
appreciate all the input!
The Stator and Rotor and Regulator were new this year. I replaced them because I had this problem late last year!
I figured it just wasn't charging enough, so I went with the 3 Phase 32 amp system. I really don't think the charging is the issue, it will charge - just won't hold charge. The battery is an Odyssey, not even 6 months old.
Since the problem appears to be intermittent, I figured it was either wiring or even the ignition system. I have had on one occasion when it at first acted like it was dead, then it spun the motor like there was never a problem!
Oh well, I still wouldn't trade her, for an '86 I guess she's entitled to be a bit tempermental
I guess the only real option is to start disconnecting items until that drain disappears.
I'll post my results......
The Stator and Rotor and Regulator were new this year. I replaced them because I had this problem late last year!
I figured it just wasn't charging enough, so I went with the 3 Phase 32 amp system. I really don't think the charging is the issue, it will charge - just won't hold charge. The battery is an Odyssey, not even 6 months old.
Since the problem appears to be intermittent, I figured it was either wiring or even the ignition system. I have had on one occasion when it at first acted like it was dead, then it spun the motor like there was never a problem!
Oh well, I still wouldn't trade her, for an '86 I guess she's entitled to be a bit tempermental
I guess the only real option is to start disconnecting items until that drain disappears.
I'll post my results......