Harley Davidson Forums

Loading


Hello

Guest

Welcome to the harley davidson forum. Join our discussion today for FREE!

CREATE ACCOUNT

Membership Benefits

Get your questions answered by harley davidson community gurus and industry experts. Exchange your experience with another members. Access full features forum. Get a members discounts for your harley parts & accessories.

2007 Sportster Idler Air Control Issue

Electrical

Reply
 
Thread Tools Display Modes
Old Sep 27th, 2010, 03:16 PM     #1
New Family
Ride: 2007 Sporster
 
Join Date: Sep 27th, 2010
Posts: 5
My Mood: My Mood
Flatliner1775 is an unknown quantity at this point
Exclamation 2007 Sportster Idler Air Control Issue

I noticed that the IAC is running when i turn the key off and is draining my battery. Can this be a short in the IAC itself?
Flatliner1775 is offline   Reply With Quote
Old Sep 27th, 2010, 03:29 PM     #2
Account Removed
Ride: 2009 Dyna Low
 
Join Date: Aug 16th, 2009
Posts: 7,235
Hoople will become famous soon enoughHoople will become famous soon enough
Re: 2007 Sportster Idler Air Control Issue

Are you sure what you are hearing is the IAC.


The IAC stepper motor actually does not "run". It normally does run for a second or two when you first turn the key on. It then goes to a pre-determined step position which it pulls from a "warm up IAC" stepper motor map.

Even though it is called a motor, it does not run or turn around and around like a normal motor does. It will step Forward to a position or limit position. Then it runs (steps) backward to a limit position. That's all it can do is run forward and then backward a bunch of steps. And to step forward or backward requires a micro-controller with software. You can't just hook the IAC motor to a battery and watch it turn or spin.... so I doubt that is what your hearing.
Hoople is offline   Reply With Quote
Old Sep 27th, 2010, 03:45 PM     #3
New Family
Ride: 2007 Sporster
 
Join Date: Sep 27th, 2010
Posts: 5
My Mood: My Mood
Flatliner1775 is an unknown quantity at this point
Re: 2007 Sportster Idler Air Control Issue

Hoople,

That is what I am hearing. After doing more research I found this:

MOCO Service Bulletin Ref TT322 July 26, 2007

July 26, 2007 - 2007 XL Models with Discharged Batteries or Very Low Voltage 2007 XL Models with Discharged Batteries or Very Low Voltage

Harley-Davidson has found some 07 Sportsters where the batteries are going dead after a night of sitting. The root cause is water intrusion. Water can run down the harness, funnel into the fuse block area, and then bridge the system relay contacts. The system relay has constant power available on the 30 terminal.
When the system relay is activated, power goes to the ECM, and then the ECM sends power out to the IAC. The IAC will then run until the battery is fully discharged.
To prevent this issue, Electrical Contact Lubricant (p/n 99861-02) can be placed on the terminals and base of the system relay, and the receptacles at the fuse block. This will create a water barrier once the relay is installed into the fuse
block.
Motorcycles exhibiting this condition could also have corrosion present, and if necessary, should have the relay terminals and receptacles cleaned with a wire brush or replaced.
Flatliner1775 is offline   Reply With Quote
Old Sep 27th, 2010, 04:06 PM     #4
Account Removed
Ride: 2009 Dyna Low
 
Join Date: Aug 16th, 2009
Posts: 7,235
Hoople will become famous soon enoughHoople will become famous soon enough
Re: 2007 Sportster Idler Air Control Issue

If you really want to know the truth, HD is incorrect. The ignition switch & Kill switch turns on the ECM. The ECM then turns on the system relay. It's not the other way around. Plus the fact the software has to loop to make the IAC step is too hard for me to believe. Trust me, it's an oversight in whoever wrote the service tip.

But that really does not matter right now because you can perform a simple trick to figure out what really is going on.

While you hear this "stepper buzzing", pull the system relay and see if the buzzing stops.

(The system relay turns on the electric fuel pump. I think that is the buzzing you hear. Like I said, you just don't apply power to an IAC motor and watch it step. It requires software to make an IAC rotate. Is HD telling me the ECM booted up and is stepping through the assembly code.)
Hoople is offline   Reply With Quote
Old Sep 27th, 2010, 04:19 PM     #5
New Family
Ride: 2007 Sporster
 
Join Date: Sep 27th, 2010
Posts: 5
My Mood: My Mood
Flatliner1775 is an unknown quantity at this point
Re: 2007 Sportster Idler Air Control Issue

I know its the IAC making the sound. I unpluged the IAC and the sounds went away. Now when I get home I will have to look at this relay they are taking about. But it looked like someone had the same issue on this fourm and this was the relay.
Flatliner1775 is offline   Reply With Quote
Old Sep 27th, 2010, 05:43 PM     #6
Account Removed
Ride: 2009 Dyna Low
 
Join Date: Aug 16th, 2009
Posts: 7,235
Hoople will become famous soon enoughHoople will become famous soon enough
Re: 2007 Sportster Idler Air Control Issue

Maybe the 2007 Sporty uses the system relay in a different way than the Dyna models like mine does (?)
On my bike it is physically impossible for a short in the system relay to boot the ECM, without also having the Kill switch in RUN and the ignition turned on. Looking at my schematics, the IAC stepper is driven off the ECM and not the system relay. There is no telling what they did different from a 2007 Sporty to a 2009 Dyna. ..

It sounds like you nailed down your problem and saved yourself a bunch of time & money. A leaky system relay WILL drain a battery. I have to print and save that tip.
Hoople is offline   Reply With Quote
Old Sep 27th, 2010, 09:47 PM     #7
Warming The Wheels
Ride: 2014 Dyna Low Rider
 
orgredneck's Avatar
 
Join Date: Sep 2nd, 2008
Location: Fleetwood,Pa
Posts: 62
orgredneck is an unknown quantity at this point
Re: 2007 Sportster Idler Air Control Issue

Re: Sporty Eating Batteries

Had this happen to my 08 sporty.
With key off listen behind air cleaner
for IAC engaging with key off.
System relay was coroied and feeding IAC.
With key off killed battery overnight.
cleaned fuse box and new system relay fixed problem.
orgredneck is offline   Reply With Quote
Old Sep 28th, 2010, 10:48 AM     #8
New Family
Ride: 2007 Sporster
 
Join Date: Sep 27th, 2010
Posts: 5
My Mood: My Mood
Flatliner1775 is an unknown quantity at this point
Smile Re: 2007 Sportster Idler Air Control Issue

Yep. I pulled the relay and check it. It was stuck closed. Going to head to the HD parts store and get a new relay. orgredneck how much did it cost?
Flatliner1775 is offline   Reply With Quote
Old Sep 28th, 2010, 01:36 PM     #9
Warming The Wheels
Ride: 2007 Ultra
 
Join Date: Mar 7th, 2010
Location: Sparks, Nv
Posts: 76
nvsteve is an unknown quantity at this point
Re: 2007 Sportster Idler Air Control Issue

Quote: Originally Posted by Hoople View Post
Maybe the 2007 Sporty uses the system relay in a different way than the Dyna models like mine does (?)
On my bike it is physically impossible for a short in the system relay to boot the ECM, without also having the Kill switch in RUN and the ignition turned on. Looking at my schematics, the IAC stepper is driven off the ECM and not the system relay. There is no telling what they did different from a 2007 Sporty to a 2009 Dyna. ..

It sounds like you nailed down your problem and saved yourself a bunch of time & money. A leaky system relay WILL drain a battery. I have to print and save that tip.
There was a change in the IAC in 08 I believe. On my 07 you can see the valve inside the throttle body outside the butterfly in the 12 o'clock position.
After 07 it's in a different place. Not sure if there was an electrical change as well.
nvsteve is offline   Reply With Quote
Old Sep 28th, 2010, 01:56 PM     #10
Account Removed
Ride: 2009 Dyna Low
 
Join Date: Aug 16th, 2009
Posts: 7,235
Hoople will become famous soon enoughHoople will become famous soon enough
Re: 2007 Sportster Idler Air Control Issue

Thanks! That just may be it. Until I come across a set of schematics for a 2007 Sporty, I will be scratching my head. I need to know why & how a shorted system relay could possibly cause an IAC stepper to Buzz.

Maybe just maybe a stepper motor was not actually used on that year/model. An ordinary servo motor could have been used also. That would explain the entire phenomenon to me. I bet that's what it is because source power would then come off the System relay.
Hoople is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
2007 FLHTC Cruise Control bikerjeff Touring Models 13 Sep 18th, 2012 10:47 PM
2007 Nightrod Starting Issue Sotnas1970 General Harley Davidson Topic 1 Apr 22nd, 2010 11:34 AM
cruise control issue Fireguy Touring Models 1 Jan 31st, 2009 05:28 AM
Forward Control Fit for FXSTC 2007 Ricochet Softail Models 0 Jan 4th, 2009 06:57 PM