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Discussion Starter · #1 ·
Hi all, I have a 2005 Dyna TC engine in my 92 FXR and am having some starting issues. Bike will not start. I have spark on both plugs when out of engine and grounded. I have an aftermarket ignition system from Thunder Heart and have replaced the module, coil and spark plugs. I also have a new battery and have checked all the ground points. I am suspecting the Crank Position Sensor is at fault and giving incorrect timing signal to the module. I have got a new sensor supposedly for a 2005 Dyna engine. This has 3 wires black, red and white. My original sensor has only 2 wires red and black. Anybody know the difference? My wiring diagram for the ignition system only shows 2 wires red and black. Anybody have the part # I need?
Thanks, Steve
 

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Three wires is a Hall effect speed sensor or old style cam sensor. Crank sensor is a two wire reluctance sensor.

32798-04C is what you'll want.

Past that, you can test that sensor. Back probe the connector and connect your VOM and crank the motor. On the AC voltage setting you should see .2 to 2.0 volts AC current. And if you have a lab scope app on your PC, you can connect the same way and watch the AC signal on the scope.
 

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Discussion Starter · #3 ·
Three wires is a Hall effect speed sensor or old style cam sensor. Crank sensor is a two wire reluctance sensor.

32798-04C is what you'll want.

Past that, you can test that sensor. Back probe the connector and connect your VOM and crank the motor. On the AC voltage setting you should see .2 to 2.0 volts AC current. And if you have a lab scope app on your PC, you can connect the same way and watch the AC signal on the scope.
Thanks Thermo, I have ordered a 32798-04C, hope that does the trick :)
 

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Discussion Starter · #4 ·
Thanks Thermo, I have ordered a 32798-04C, hope that does the trick :)
Thermo, I have just recieved a 32798-04C Crank Position Sensor and this has also 3 wires, Red, Black and White.
Do I just not connect the White wire? I mention that this CPS is aftermarket, do I have to have an OEM one?
Incidentally, I have run this system since 2009 with no problems. A relatively simple system from Thunder Heart Stand Alone Ignition.
269898
 

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Discussion Starter · #5 ·
Thermo, You see from the above that I only had 2 wires from the CPS to the ignition module.
 

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I looked up the wiring diagram for your bike and it shows a 2 wire sensor, but no number. When I searched the number that Therm sent you, it shows a 2 wire sensor. Are you sure you didn't receive a speed sensor which is 3 wire, but for the tranny and speedometer?
 

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Discussion Starter · #7 ·
Fatbagger, Thanks for the response, you are correct. It seems I got a Cam position sensor and not a Crank position sensor. The part number is correct but the item is wrong. That's what you get from ordering from an aftermarket source and $88! Now I will have to order a new one from my nearest HD dealer.
 

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One thing I also see, the 32798-04c has a shorter wire tail with a molded plug, used on 04-05 dyna's, a 32798-00 looks to be the same sensor but with a longer tail and no plug, but wire ends. Looks like you don't have a 04-05 bike so might be worth a look.
 

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Discussion Starter · #9 ·
Thanks for that. I have actually an FXR with a 2005 (suppose could be 2004 production) Dyna engine and ThunderHeart Stand Alone Ignition that is giving me trouble. I have to cut off the moulded contact anyway and solder the CPS in. I have run this setup since 2009.
Do you think the 32798-00 magnetic tip will be the same length as the 32798-04C? Otherwise looks good.
 

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Fatbagger, Thanks for the response, you are correct. It seems I got a Cam position sensor and not a Crank position sensor. The part number is correct but the item is wrong. That's what you get from ordering from an aftermarket source and $88! Now I will have to order a new one from my nearest HD dealer.
Stop calling it a CPS. CPS is Cam Position Sensor. You want a CKP if you need a Crankshaft Position Sensor.
 

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Honestly, I'm not going to say I know for sure. But the 32798 should mean the sensor with the -00 being the year that particular part was introduced (2000) and the -04 (2004) being a revision to that original version, probably the addition of the molded plug. The addition of an A or B or C last digit usually mean the same part but supplied from a different supplier to HD.
 

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I reached out to one of the guys at Thunderheart and he says that system must use a 32707-01 sensor. Not the sensor that came with the motor. And that its clearly stated in the instructions.

I have a 32707-01 in my hand, and it has 2 pins in the connector.
 

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Stop calling it a CPS. CPS is Cam Position Sensor. You want a CKP if you need a Crankshaft Position Sensor.
This is true, but then cam sensors where last used in 2000, so there isn't one on this motor. When I did a search with the part number one site came up with it being a crank speed sensor (WTF) and showed a tranny speed sensor, not even close.
 

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I reached out to one of the guys at Thunderheart and he says that system must use a 32707-01 sensor. Not the sensor that came with the motor. And that its clearly stated in the instructions.

I have a 32707-01 in my hand, and it has 2 pins in the connector.
Isn't that used on softail "b" motors, I know the wire enters the sensor from a different angle, from the location of the mounting bolt lug, the 32707-01 enter from the side (90*) and the 32798-00 or 04 enter from across from the bolt (180*). Maybe it doesn't matter. Just putting it out there.
 

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Discussion Starter · #17 · (Edited)
I reached out to one of the guys at Thunderheart and he says that system must use a 32707-01 sensor. Not the sensor that came with the motor. And that its clearly stated in the instructions.

I have a 32707-01 in my hand, and it has 2 pins in the connector.
Thanks for the Research and the info. Any idea what the different part numbers on these sensors indicate as they all have the same application?
The 32798-04C I have here has also 2 pins in the moulded connector but 3 wires when I peeled back the insulation. I have to solder the wires to the sensor as I have a custom build.
 

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Discussion Starter · #18 ·
Honestly, I'm not going to say I know for sure. But the 32798 should mean the sensor with the -00 being the year that particular part was introduced (2000) and the -04 (2004) being a revision to that original version, probably the addition of the molded plug. The addition of an A or B or C last digit usually mean the same part but supplied from a different supplier to HD.
Thanks for the info.
 

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Isn't that used on softail "b" motors, I know the wire enters the sensor from a different angle, from the location of the mounting bolt lug, the 32707-01 enter from the side (90*) and the 32798-00 or 04 enter from across from the bolt (180*). Maybe it doesn't matter. Just putting it out there.
The one in my hand is used on late twin cams, this one came out of a 2011.

The cable comes out 90 degrees away from the bolt boss.

Thunderhart was pretty adamant about using that sensor and only that sensor.
 

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Discussion Starter · #20 ·
The one in my hand is used on late twin cams, this one came out of a 2011.

The cable comes out 90 degrees away from the bolt boss.

Thunderhart was pretty adamant about using that sensor and only that sensor.
Right. I would hate to order a 32707-01 sensor only to find 3 wires when I remove the moulded plug in order to solder the wires to the module, which happened with the 32798-04C. Looks like the wires are 90 deg. and above the bolt boss too me, that probably doesn't matter though.
 
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