I been watch'n too much You Tube............

Joined
Mar 1, 2024
Messages
18
Age
52
Location
wtvl
For a while now I've been thinking about coast-to-coast touring. I realized, although I'm a Merchant Marine, meaning not a bad mechanic, I haven't much of a clue about wiring harnesses/switches or the mechanicals of the ST. So, I picked up a 2003 barn find to jump right into it. On the way home I stopped for gas and found 2 little mice looking up at me in the trailer. Figured those little guys are about to teach me all I need to know. Here's what I found. Mouse Utopia, living in my in the throttle body assembly, as well as several dead mice in the ECM. I ordered up a new Sub Harness at the local Honda shop. Removed the Main wiring harness and retaped and reworked the wiring harness including the recall ground. I took off the fuel tank, air box, throttle body assembly, and vacuumed out about a medium sized beach ball of Mouse Love. I took out the rubber shield and the alternator was encased in Mice. Glad I took off that rubber shield. I loosened up the 4 bolts for the lower fuel tank as well as the inner rear fender. It took a couple of small blocks of wood to tap into place to make a little space for the harnesses and relays, as well as removing 1 bolt, from the frame to make some room. It all came out pretty well, and with a new taped harness install was half time. While in there, had to rewire the cooling pump ground, I cleaned out the vacuum lines and already perfectly clean 5-way valves. Careful cause they're little and plastic. Cleaned and made up all electrical connections, All F1 codes cleared. Blinking fuel bar alarms cleared. BUT still no start. No spark to any plugs. That'll be next thread. Thought this might help someone out.
 

Attachments

  • P3010113.JPG
    P3010113.JPG
    247.6 KB · Views: 143
  • P3010107.JPG
    P3010107.JPG
    256.4 KB · Views: 142
  • P3070136.JPG
    P3070136.JPG
    192.8 KB · Views: 133
  • P3080150.JPG
    P3080150.JPG
    200.1 KB · Views: 132
  • P3080151.JPG
    P3080151.JPG
    147.4 KB · Views: 132
  • P3080192.JPG
    P3080192.JPG
    340.5 KB · Views: 131
  • P3080186.JPG
    P3080186.JPG
    179.9 KB · Views: 125
Welcome to the forum from Cornwall UK! Looks like you've been a busy boy. Congratulations on your ST, hope you get loads of Smiles from her when finished. Please post more photos when done.
 
Welcome to the forum from Southern Utah!

Congrats on your :slv13:

Good luck with the clean up! :hat3:
 
Greetings & Salutations!!! :wave:

Good job on restoration and repairs! No spark is most likely safety interloc switches or connectors or wiring.
 
Before you spend all your time, and hard earned money, trying to bring the bike back to its glory days, I'd check to see if the ECU is working correctly, as they are no longer available for the early year bikes.
Welcome to the forum, and good job so far on the project.
 
Welcome aboard.

While you were in there working on the 5 way T, did you extend the lines and position the T above the throttle bodies? This has been mentioned in other threads. The purpose is to make the T more accessible for future clean outs.
 
Extending the lines turns them into a kitchen sink trap, and clogs up easier/faster.
You want the lines about a half inch more than stock, just so it stands up enough to keep the five way clear.
 
Welcome aboard.

While you were in there working on the 5 way T, did you extend the lines and position the T above the throttle bodies? This has been mentioned in other threads. The purpose is to make the T more accessible for future clean outs.
 
I was actually able clean out and untangle the vac lines from the throttle body sensor wiring. It actually had some extra room under the fuel rails. Those Honda engineers must have some really small hands...........
 
I was actually able clean out and untangle the vac lines from the throttle body sensor wiring. It actually had some extra room under the fuel rails. Those Honda engineers must have some really small hands...........
Surprisingly,
Before you spend all your time, and hard earned money, trying to bring the bike back to its glory days, I'd check to see if the ECU is working correctly, as they are no longer available for the early year bikes.
Welcome to the forum, and good job so far on the project.
I picked up a PoPo ECM A31 Model, its Limited to 120MPH. Didn't fix the no spark problem. Cleaned out the start stop switch. No debris at all. I just used contact cleaner. All relays and fuses have power, conductivity. Took out the Bank Angle switch. Turned it upside down, could hear the relay contacts close. New Battery is getting 12.72 across the Batt on start-up. Fuel Pump relay closes and then F/O pump strokes. Good fuel psi on the return fuel racks. No interlock there anyway. Ignition switch, sends power to fuse "C,D" and then to coil packs. No spark after that.
 
Last edited:
Still no codes? Assuming you successfully repaired the engine harness there are two plugs with the same shape. I believe it’s easy to confuse which sensor they go to. There are no-start threads here referring to which sensors. Cam or crank and temp sensor??? In this case the ECM won’t switch the coils on and off thus no spark. There could be no FI light as this generation ECM just sees a sensor and isn’t smart enough to know what’s missing.
 
Re: The two sensors mentioned above.

It is easy to mix up the connectors for the cam position sensor and the evaporative cannister purge solenoid as they both use the same connector and either one will plug in to either sensor. Fortunately they are two different colors. The blue connector goes to the evap cannister solenoid.
 
Still no codes? Assuming you successfully repaired the engine harness there are two plugs with the same shape. I believe it’s easy to confuse which sensor they go to. There are no-start threads here referring to which sensors. Cam or crank and temp sensor??? In this case the ECM won’t switch the coils on and off thus no spark. There could be no FI light as this generation ECM just sees a sensor and isn’t smart enough to know what’s missing.
[/QU My famous last words "No matter what, I'm not gonna be outsmarted by those 2 mice." Is there any way to test the ECM? Just to check the BLU/Y and the Y/BLU or to see if anything comes from any other 25 pins? I'm getting BL/Wh power to coils. Is there a master list of "No spark, No start" switches somewhere? The main harness, I just removed, to visually inspect/basically learn my first FI system, and then just took continuity checks where I could. I didn't see any damage to the Main harness just the sub throttle body harness. I rewrapped the main harness, cleaned up all plugs/contacts, as some of them had white corrosion. I hit everything with contact spray. All FI codes cleared. Like you stated, its starting interlocks from here.
 

Attachments

  • P1010239.JPG
    P1010239.JPG
    197.4 KB · Views: 23
  • P1010237.JPG
    P1010237.JPG
    182.3 KB · Views: 24
  • P1010235.JPG
    P1010235.JPG
    205.8 KB · Views: 24
  • P1010236.JPG
    P1010236.JPG
    169.6 KB · Views: 23
Re: The two sensors mentioned above.

It is easy to mix up the connectors for the cam position sensor and the evaporative cannister purge solenoid as they both use the same connector and either one will plug in to either sensor. Fortunately they are two different colors. The blue connector goes to the evap cannister solenoid.
I paint penned and photo'd the connections before I removed the Sub harness, and you're right, I mixed those 2 up. Fortunately, caught it. Wouldn't FI blink ? All part of the FI monitoring system?
 
What's this little red plug guy? W diagram says service connector. Anybody have any luck troubleshooting the ECM with this plug? Notice the plastic in the back. Thats how much the mice ate away at the plastic............Also, is there a quick reference guide on the different connector plug names. I split open a double female terminal with a fluke meter. Thanks again.
 

Attachments

  • P3080138.JPG
    P3080138.JPG
    161.3 KB · Views: 24
Top Bottom