Induction module/throttle body - 07 Softail
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3rd Gear
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Induction module/throttle body - 07 Softail
So I have a 07 heritage softail. This is my first Harley to ever work on. But I have a lot of mechanical skills with other bik
es/small eengines. I have replaced a lot on this bike but need some serious help because I'm a rookie when it comes to my Harley. So I loand it to my brother and one night by t he calls and says he road to Walmart went in came out and wouldn't start. We'll after that I was able to get it to start but would stall n die right away. So since all that I have replaced the map sensor because the built in diag system throwing low voltage. I've tripped check everything. But I believe my is. I'm having issues with gasket alignment from throttle body to cylinders
es/small eengines. I have replaced a lot on this bike but need some serious help because I'm a rookie when it comes to my Harley. So I loand it to my brother and one night by t he calls and says he road to Walmart went in came out and wouldn't start. We'll after that I was able to get it to start but would stall n die right away. So since all that I have replaced the map sensor because the built in diag system throwing low voltage. I've tripped check everything. But I believe my is. I'm having issues with gasket alignment from throttle body to cylinders
HDF Community Team
Joined: Aug 2007
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From: Sydney Australia
@rednsawyer I have moved this thread from the Welcome section to the Softail Models section as you will get better responses to your question in this section. The Welcome section is more for introducing yourself & letting other forum members know what Harley Davidson you own, not asking technical questions.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,300
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From: Honah Lee
Does it have security?
https://www.hdforums.com/forum/sport...-start-up.html
What is the code your seeing for throwing low voltage. Maybe starting with a U, P or a B.
There more than one low, pointing to different issues.
When it start up briefly, try catching it by opening the throttle to see if it will run.
Can you nurse it in running briefly with a fuel misted into intake with air filter off.
Just trying to determine is it a fuel issue over electrical. It takes a special adapter to check fuel pressure most don't have access to.
Do you think you manifold fit is leaking so bad that's the issue?
PS.. Welcome to the HDFORUM.
https://www.hdforums.com/forum/sport...-start-up.html
What is the code your seeing for throwing low voltage. Maybe starting with a U, P or a B.
There more than one low, pointing to different issues.
When it start up briefly, try catching it by opening the throttle to see if it will run.
Can you nurse it in running briefly with a fuel misted into intake with air filter off.
Just trying to determine is it a fuel issue over electrical. It takes a special adapter to check fuel pressure most don't have access to.
Do you think you manifold fit is leaking so bad that's the issue?
PS.. Welcome to the HDFORUM.
Last edited by Jackie Paper; Apr 7, 2026 at 07:33 AM.
Seasoned HDF Member
Joined: Sep 2008
Posts: 14,068
Likes: 11,086
From: San Diego, CA
So I have a 07 heritage softail. This is my first Harley to ever work on. But I have a lot of mechanical skills with other bik
es/small eengines. I have replaced a lot on this bike but need some serious help because I'm a rookie when it comes to my Harley. So I loand it to my brother and one night by t he calls and says he road to Walmart went in came out and wouldn't start. We'll after that I was able to get it to start but would stall n die right away. So since all that I have replaced the map sensor because the built in diag system throwing low voltage. I've tripped check everything. But I believe my is. I'm having issues with gasket alignment from throttle body to cylinders
es/small eengines. I have replaced a lot on this bike but need some serious help because I'm a rookie when it comes to my Harley. So I loand it to my brother and one night by t he calls and says he road to Walmart went in came out and wouldn't start. We'll after that I was able to get it to start but would stall n die right away. So since all that I have replaced the map sensor because the built in diag system throwing low voltage. I've tripped check everything. But I believe my is. I'm having issues with gasket alignment from throttle body to cylinders
Hard to follow...
Are you saying it threw a low voltage diagnostic code?
Based on that code, first three things I'd do would be check battery (load test, not just voltage check), the cables, both ends (especially the ground to the frame), and the then the ignition switch.
I'd start with the easy stuff, and work my way to the more involved stuff....
The softails have been known to have the battery ground cable (-) come loose where it attaches to the frame, under the front of the seat. That can lead to numerous codes and all sorts of running, stalling, and electrical issues.
Next, the ignition switch on the tank console is known to have the contacts in the switch get dirty, and wreak havoc with starting and stalling. They don't sell the parts of that switch individually, but I have disassembled mine (take pics every step of the way. There are some small parts you need to get back together correctly). I cleaned it real well, re-greased it, and it solved some starting issues I once had.
Once a good power source, cables, and ignition switch are confirmed, if the problem persists, then I'd check the fuel pressure as suggested by 98hotrodfatboy.
Good luck with your repair...
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,007
Likes: 7,541
From: Poolville
Hard to follow...
Are you saying it threw a low voltage diagnostic code?
Based on that code, first three things I'd do would be check battery (load test, not just voltage check), the cables, both ends (especially the ground to the frame), and the then the ignition switch.
I'd start with the easy stuff, and work my way to the more involved stuff....
The softails have been known to have the battery ground cable (-) come loose where it attaches to the frame, under the front of the seat. That can lead to numerous codes and all sorts of running, stalling, and electrical issues.
Next, the ignition switch on the tank console is known to have the contacts in the switch get dirty, and wreak havoc with starting and stalling. They don't sell the parts of that switch individually, but I have disassembled mine (take pics every step of the way. There are some small parts you need to get back together correctly). I cleaned it real well, re-greased it, and it solved some starting issues I once had.
Once a good power source, cables, and ignition switch are confirmed, if the problem persists, then I'd check the fuel pressure as suggested by 98hotrodfatboy.
Good luck with your repair...
Are you saying it threw a low voltage diagnostic code?
Based on that code, first three things I'd do would be check battery (load test, not just voltage check), the cables, both ends (especially the ground to the frame), and the then the ignition switch.
I'd start with the easy stuff, and work my way to the more involved stuff....
The softails have been known to have the battery ground cable (-) come loose where it attaches to the frame, under the front of the seat. That can lead to numerous codes and all sorts of running, stalling, and electrical issues.
Next, the ignition switch on the tank console is known to have the contacts in the switch get dirty, and wreak havoc with starting and stalling. They don't sell the parts of that switch individually, but I have disassembled mine (take pics every step of the way. There are some small parts you need to get back together correctly). I cleaned it real well, re-greased it, and it solved some starting issues I once had.
Once a good power source, cables, and ignition switch are confirmed, if the problem persists, then I'd check the fuel pressure as suggested by 98hotrodfatboy.
Good luck with your repair...
You might be on to something @hattitude , I had forgotten that I recently worked on a buddy's bike, an 07 Street Glide.. It would start and run for 30 seconds maybe and then shut off and if you wait a bit you could restart it but it kept doing that. Other people were telling him you got a fuel problem after I had already diagnosed excellent fuel pressure and ruled that out.. They were telling him that you got that replaced the fuel pump and I kept telling my buddy, I said no there's something else going on because when it starts sometimes it starts good sometimes and sometimes it starts hard but it always stalls and dies within 30 seconds. Like the ECM was shutting it down.. Through some diagnosing I have found that the charging system was only supplying 12.6v@2000rpm and fivured the ECM was shutting the bike down because it didn't see the proper voltage.. So we replaced the regulator and all his other problems disappeared including the radio coming on all by itself, weird... He says to me the other night that he finally got the bike out for a good ride and it never ran this good since he owned it.
So yeah OP completely test your charging system..
Last edited by 98hotrodfatboy; Apr 7, 2026 at 10:41 AM.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,300
Likes: 6,325
From: Honah Lee
Softail TCb 's' loosen there ground or the battery attachment for the negative wire because the OEM seat has buttons on it to hold battery. Some aftermarket seats don't have the buttons.
I lost the battery attachment twice before locking the battery down with hard rubber shims.
My seat was a Corbin two up. No buttons for the battery on it. The negative cable is short. Attaches to the frame just a few inches away. Any fwd or aft movement of battery is on cable.
I lost the battery attachment twice before locking the battery down with hard rubber shims.
My seat was a Corbin two up. No buttons for the battery on it. The negative cable is short. Attaches to the frame just a few inches away. Any fwd or aft movement of battery is on cable.
Last edited by Jackie Paper; Apr 7, 2026 at 10:47 AM.
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Seasoned HDF Member
Joined: Sep 2008
Posts: 14,068
Likes: 11,086
From: San Diego, CA
I've had both the loose ground cable and the dirty ignition switch affect the starting & running on the 2003 Heritage I bought new and still have....
First it was the ground cable... Second time, I went straight to the ground cable again, but it was fine. That's when a little research suggested the ignition switch was dirty. I disassembled and cleaned that, and haven't had a recurrence of starting/running issues since....
So far, no stator or regulator issues.... at least not yet...
First it was the ground cable... Second time, I went straight to the ground cable again, but it was fine. That's when a little research suggested the ignition switch was dirty. I disassembled and cleaned that, and haven't had a recurrence of starting/running issues since....
So far, no stator or regulator issues.... at least not yet...
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Thread Starter
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3rd Gear
Joined: Apr 2026
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So yes when these problems started the bike would start and die within 30 seconds. Was giving a po107 MAP sensor code replaced the map sensor and it would stay running after that code would come on the go off. I had a pin hole in fuel line inside take and issues with the fuel not reading so then just replaced everything inside the tank. Also have replaced ceank sensor,iac sensor, and doing all that so I just decided to go ahead and replace the gaskets for induction/throttle body