When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey guys, I've had the bolt that holds the cable on the + battery terminal rub through a wire, easy fix I thought, so I cut out the damaged section of wire and soldered it back together, plus heat shrink etc. etc. No go, bike still cranks but won't fire. Everything seemed to work except fuel was intermittently cutting out and couldn't get fuel pressure. One time when it decided to prime I heard bubbles in the tank changed hoses, got fuel pressure blah blah blah. Still cranks, won't fire. Spent my whole weekend chasing wires and looking for shorts and found nothing. Replaced system and start relays and cleaned and checked all fuses, still no go. I was flicking through the wiring diagrams and spotted, you guessed it, 30a circuit breaker! I thought where the hell is that, I don't remember seeing it with the fuses and relays and after much searching found it hidden behind the rear inner guard (stupid place) Anyway Ill put up a photo of it soon, to me it looks totally wrecked. I'm not much of an electrical guy but figured if I checked for continuity between the two posts I would hear the beep from the DVM and if it's open (no beep from meter) it's cooked. Is that right? My next question is, when I get a new one tomorrow, do I need to be checking things like the voltage regulator before I try to fire it up again? Are there other things I could have fried besides the breaker when the battery shorted? Or is that the breaker doing it's job, to stop other components getting fried?
Any suggestions greatly appreciated. Sorry if it was a bit long winded!
Thanks, Matt.
One more thing I forgot to ask is, if that breaker is to blame wouldn't that just kill power to everything? Lights, dash etc all still working.
Cheers.
Seems like Harley replaced the circuit breaker with a 40 amp maxi-fuse in 2007. Some people are retrofitting their rides with the new type fuse.
The real problem was a bad crimp on an eyelet overheating the breaker. The fuse was implemented before HD figured that out but they don't undo recalls. THe fuse won't blow from heat, but a breaker will. Best thing to do is feel the wires or shoot them with a temp gun when powered on/running and look for high temp on one.
Thanks for the replies guys! Would it be fairly safe to assume that if it's the original breaker and it lasted 11 years that the crimps are ok? I think the breaker blew when the pos batt terminal shorted. But I will do as you said with temp gun and see what I find. Thanks again. Matt.
Well, disappointment doesn't even begin to describe what I'm feeling right now!! The 30a cb was definitely buggered. New one in, connections cleaned and greased and no go!
Checked fuses all ok. While I had the fuses out I thought Id chuck the meter on.
Headlight 12.71v
Fuel Pump 0.00v
ECM 1.15v
I can understand if I messed something up in the tank when I was in there, left a plug off or something, I'm 99.9% sure I didn't. But what I don't get is the 1.15v to the ECM.
I'm really bad at this. Checked again ECM fuse has 12.54v from 1 side to the - battery terminal. I was trying to read what would have been going through the fuse itself and got that weird reading. Does that mean I've got power to the fuse but it's not getting through somehow? I'm just taking shots in the dark now, as you can probably tell, I don't really know what I'm doing!!!
Also after a quick search of the forum here, my understanding now is that power to fuel pump is cut if the CKP can't detect the motor turning. Again not entirely sure.
I'm getting desperate here, I really don't want to trailer it to those thieving bastards down the road to fix it!!
Thanks
No power at all to either side of fuel pump fuse, even with meter connected when ignition is first turned on. BUT, the pump came on just long enough to prime, then I couldn't get to do it again, but the relays started clicking again!
Matt,
Do you have the schematics? if not look at these and see if they are relevant to your bike.
Re-read your original post and see you do have schematics.
Reading through the links Larsfum gave I would replace the CB with a fuse and ohm out the wires that go to and from the CB, wiggle while checking, (I'd Replace them if I changed to a fuse). Make sure your battery is charged and in good shape, load test it. Check your ground connections 1&2 and 3.
With the ignition off you should have 12V to ground at both the Battery, ECM fuse and the Common of the System Relay. You can check the ECM fuse voltage at the ECM by disconnecting 78 A-B and checking the BE/GY wire at the connector slot 31 in the drawing I posted. Pull the system relay and you should have 12V from the ECM fuse at the Common lug, it supplies the 12V to the fuel pump when the system relay is energized.
Battery Fuse supplies 12V to TSSM and can be checked at connector 30A-B.
When you turn the Ignition on the R/GY and R/BK wire from the switch to the fuse block are energized. The Ignition fuse GY wire sends 12V to the TSSM and to the run/stop switch at the right hand controls. When the switch is put in the run position it supplies 12V W/BK to the Start Button, ECM Switch Power and to the coil of the System relay. The ECM provides the ground for the system relay GN/O for 2 seconds, ( fuel pump will run), and if there is no input from CKP sensor the ground from ECM opens shutting the Fuel pump off. When the System Relay is engaged the ECM 12V energizes the Y/GN wire that provides 12V to the Fuel Pump fuse, Fuel Injectors and Ignition Coil.
Hope this helps, make some checks and let us know what you find.
Bill
Thanks Bill, I appreciate that! I have checked the majority of those things, but there's some I haven't. After realizing how terrible my haynes manual wiring diagrams were I went and downloaded the very same ones from your pics. They are 100% better than what I had and they have now lead me in a new direction. I'm thinking it's the Vehicle Speed Sensor. I'll be replacing it today and will report back, if that's not it then you've given me a great list of other things to check.
Thanks, Matt.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
30a Circuit Breaker
