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Only getting 4.8 volts at the coil

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  #11  
Old 06-24-2019, 01:37 PM
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Originally Posted by olkarz
Max Head I'm getting 5.4v at the fuel pump connector wire yellow with green stripe.

At the fuel pump relay, when I hit the switch I'm getting 12v then it drops to 9.7v, but I'm still only getting 4.8v at the coil connector.

I swapped the fuel pump relay connector to the relay right beside it but no changes.

Is there some type of immobilizer circuit that's built into the ECM that would deactivate the coil or pump when a accident is sensed? I'm stuck know. Other than slicing the cover on the whole harness under the tank and checking each and every wire.
At this point I need a diagnostic tool to see what code the ECM is recording.

Sounds like you have a short in your fuel pump. Not sure why the fuse is not blowing. Start disconnecting things and checking voltages. EFI fuses are separate from main fuses IIRC. Do not leave the power on for any period of time. You can burn up the wire.
 
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Old 06-24-2019, 01:42 PM
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Does the fuel pump and ignition coil run off of the same relay? The pump is pumping fuel. I can see it spraying out of the heads when I attempt to crank the bike.

That should the voltage be at the fuel pump connector?
 
  #13  
Old 06-24-2019, 03:01 PM
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Originally Posted by olkarz
Does the fuel pump and ignition coil run off of the same relay? The pump is pumping fuel. I can see it spraying out of the heads when I attempt to crank the bike.

That should the voltage be at the fuel pump connector?

It should be battery voltage minus a volt at most. . Look at the wiring diagram. Power comes from the main circuit breaker, directly to the fuse block then to the relay. From the relay it goes to the coil and fuel pump. You either have excessive current draw or a number of bad connections in the line. I'd look at the wire going to the main circuit breaker. Turn the ignition / run-stop on, let the pump cycle. Feel for a hot terminal. Look at the relay socket. Make sure the terminals are clean and crimps tight.
 
  #14  
Old 06-25-2019, 07:54 AM
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Just curious, did you try the suggestion above to run a wire directly from battery to coil and see if the plugs fire? If that works it will narrow done the connections to double check, including ignition switch.
Good Luck finding the problem. It would be really nice if you can avoid involving the shop.
 
  #15  
Old 06-25-2019, 08:22 AM
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Do you have a good battery installed in the bike?
 
  #16  
Old 06-26-2019, 08:21 AM
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Not sure about all of the connectors that you have pics of, but that is the correct Cam Position Sensor in the nose cone.

You should be getting +12VDC at the fuel pump connector under the console. You do not have enough juice in that battery pack to start this bike. Voltage should stay above +12VDC while cranking. Get a good battery, and repeat the tests. You'll need it when you get the bike fixed anyhow.
 
  #17  
Old 06-26-2019, 09:46 AM
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Originally Posted by larsfum
Not sure about all of the connectors that you have pics of, but that is the correct Cam Position Sensor in the nose cone.

You should be getting +12VDC at the fuel pump connector under the console. You do not have enough juice in that battery pack to start this bike. Voltage should stay above +12VDC while cranking. Get a good battery, and repeat the tests. You'll need it when you get the bike fixed anyhow.
More correctly, it needs to stay above 9.5 volts during cranking.
 

Last edited by Max Headflow; 06-26-2019 at 10:10 AM. Reason: typo
  #18  
Old 07-08-2019, 12:21 PM
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Cut the wiring cover from the coil connector down to the ECM and there isn't a break anywhere in the wire.

Measured the voltage at the fuel pump and I'm getting 12.5v at the fuel pump connector, but still only 4.9v at the coil connect.

Connect a +12v wire, from this red w/white stripe directly to the coil connector and the coil started smoking....
Coil pack is completely cooked now.

coil wire connector colors:
Gray w/pink strip - connected to the ECM.
Red w/white stripe - connected to a common 12v bundle the connects to the fuse box.
Black w/white stripe - connected to a common ground.

The 2 relays next to the ECM: 1 goes to the fuel pump and the other goes to the injectors. Both are working.
Relay under the see provides power to the batwing electronics. All a working correctly.
 
  #19  
Old 07-08-2019, 07:00 PM
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What coil are you talking about?

I get yellow/blue, yellow/green, and blue/orange.

 
  #20  
Old 07-09-2019, 09:55 AM
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Originally Posted by Max Headflow
What coil are you talking about?

I get yellow/blue, yellow/green, and blue/orange.

I'll take another look at the connectors that will reach the coil, but the colors are gray w/purple stripe that goes to the ecm
Red w/white stripe that connects to a common 12v
Black w/white stripe that connects to a common ground.
It is the only wire that will reach the coil. The only other connectors that's close to the coil are the 1s for the fuel injectors, and they are too big to fit.
The throttle position sensor wire isn't long enough to reach the coil pack, so that connector colors that I mentioned is all that is left.

The VIN on the frame says that the bike is a 2001 Electra Glide Classic with fuel injection... Whether that's the correct wiring harness for it or the correct motor that came on it from the factory I can't say for sure.
 


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