I was hoping to get a little help on an issue. I've had my '05 Softail up on the lift table for about 6 months without touching it. (New kid and honey do chore) Anyway, I go to try to start it, no joy, battery dead. I try to jump it and the compression doesn't really let it turn over. So I pull the plugs to see if it'll crank. It does, but no spark. I check the constant hot at the coil and it's dead. After a little investigation, I assume the System relay is dead not sending power to the coil. Replace the system relay and still no power. So then I got smart and jumped the 2 pins the relay would power, pins 30 and 87 I believe. Bike fires up.

So apparent there isn't power to the system relay. Check for voltage at the relay and pin 85 is dead. Trace back pin 85 to pin 4 at the ECM and check for continuity, which I have. So it appears I'm not getting power at pin 4 through the ECM. Does this just mean the ECM is dead or is there something else that tells the ECM to send power through that pin.

I'm relatively stupid when it comes to wiring but I have the wiring manual and that has gotten me here. So is there magic inside the ECM that has crapped out or am I missing something? Any help is greatly appreciated!

 

Check the easy things first, Is the security system on? Is the run switch on run?

 

If your battery is that dead/bad, even with jumping, you may have trouble. Fix that first by either charging the battery with a charger, not the trickle charger, or replacing the battery.

 

^^^ That's very true. Also, if you have a piggy back tuner, they need a stronger battery than a bike with no tuner - my battery was getting weak and wouldn't start the bike with the tuner but it would without the tuner. The battery would go to 8 volts when cranking which was enough for the stock computer but not enough for the tuner. I got a new tuner under warranty thinking it was the culprit but it was not. New battery and I was good to go with my old tuner.

And my battery was only 1.5 years old and had been on the trickle all the time when not riding... expensive HD battery too. I hope my new Advanced Auto battery lasts longer.

 

Just in case you were checking for spark with the plugs still out, you need spark plugs in the heads for compression to be sensed to get a spark.
I would imagine the ECM is looking for the slowing down of the crank under the compression stroke via CKP sensor signals to then give an earth to the system relay to allow it to operate. Once the relay is activated this then sends power to the coil, injectors and fuel pump. So unless you are cranking the engine with sufficient power or are checking for coil power within the first couple of seconds of the ignition being turned on ( when you hear the fuel pump prime) , there will be no power at the coil as this is also receives power on the same wire for those first couple of seconds and then shuts down like the pump and waits for cranking.
Hopefully your no spark issue is as simple as that and a poorly charged battery.
You initially had a flat battery, did you charge it before jumping the relay pins?

 

Well after replacing the relay, I was doing all my wire checks having replaced the battery with a fresh one from Harley. Looking at my manual, it appeared that the coil connector and and other leg of the relay should be receiving constant power. I pulled the crank pos relay, cleaned it and put it back together to give everything a try and it all fired back up! So I'm assuming I wasted my weekend messing with it, and wasted the cost of the relay, but it's back together and running! Thanks for all the help! I need to get smarter on this wiring junk

 

You didn't waste time at all, you learned how your bike works. I was stranded on the side of the road on a buddy's bike a couple of weeks ago; it was years of figuring things out that got me back up and running again. Every experience like yours teaches you something that will pay off later.

So was your problem a bad connection on a crank position sensor relay or the crank position sensor itself? I didn't realize there was a relay on that sensor, it is unusual to have a relay on a sensor, but I haven't memorized the wiring diagram.

I did a quick search and it seems the crank position sensor does go bad from time to time and causes the problems you had and that it can be intermittent. I had a high idle problem with mine, replaced the idle air controller but it turned out to be the throttle position sensor.

Sometimes I miss points and a carb.

 

wondering.. have you checked to see if you bike is throwing any codes....