Tach problem

Hammitt

Hammitt

Member
Tach just went out on my 04 chopper.
The dealer says its the tach ring. Part is 100 bucks.
Ouch. Probably wouldn't worry with it, but when it went out, the whole tach lit up and it bugs the hell out of me seeing those lights.
Is this a common problem, or is there a better fix than replacement part?
Thanks
 
T

TheDeadOne

Banned
yep, replace, sometimes, rarely, a tach can affect the signal coming from the coil negatively and cause ignition issues as well. Don't take any chances, just go ahead and replace.

Just my thoughts here! Good Luck! :2thumbs::2thumbs:
 
Keith S

Keith S

EHC FREE!!!!
I put a Crane Hi-4 ignition on my 04 chopper. Ever since then, the tach has been messed up (reads double - I am assuming because of the double vs single pickup sensor). It is annoying, but not an issue. I have no idea how a tach could affect the coil. The signal to the coil is completely separate.

Do a search and you can find an 04 Wiring diagram. If you can't find it, just PM me and I will send you one.
 
T

TheDeadOne

Banned
Keith S said:
I put a Crane Hi-4 ignition on my 04 chopper. Ever since then, the tach has been messed up (reads double - I am assuming because of the double vs single pickup sensor). It is annoying, but not an issue. I have no idea how a tach could affect the coil. The signal to the coil is completely separate.

Do a search and you can find an 04 Wiring diagram. If you can't find it, just PM me and I will send you one.
Click to expand...
The tach signal is "generated" from one side of the coil connections! :D
If the tach shorts or just starts sending an improper signal "back" to the coil, known as "back feeding" could cause troubles for the ignition.
 
DRBarnhart

DRBarnhart

Insert title here...
TheDeadOne said:
The tach signal is "generated" from one side of the coil connections! :D
If the tach shorts or just starts sending an improper signal "back" to the coil, known as "back feeding" could cause troubles for the ignition.
Click to expand...
I have to disagree with you here Dead. The "tach" signal is produced by the ignition module and so is the trigger to the coil but they're not on the same wire. I think the only way the tach signal could affect the ignition system would be if it had a dead short to ground because that would affect the ignition module.

:zz2cents:

Dennis
 
T

TheDeadOne

Banned
DRBarnhart said:
I have to disagree with you here Dead. The "tach" signal is produced by the ignition module and so is the trigger to the coil but they're not on the same wire. I think the only way the tach signal could affect the ignition system would be if it had a dead short to ground because that would affect the ignition module.

:zz2cents:

Dennis
Click to expand...
That's what I'm saying. :D And they are connected internally inside the ign. module. Crank Sensor just gives a (ground) pulse to tell the ignition to discharge the coil one cylinder or the other. Coil provides a (positive) pulse signal through the ignition then goes through the EHC, tees off inside the EHC which records the RPMS, then continues to the tach. That coil pulse signal is what provides for the blinking LEDs on the ignition when running.

Now something wrong inside the EHC could very well cause a problem at the tach. or the ignition as well.

Boy you guys are getting so "indepth'ly" technical on me! :D

I think it's GREAT! :2thumbs::2thumbs:

Whats next? :cheers:
 
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T

TheDeadOne

Banned
Nope, I don't have the internal schem. for the ignition. I'd hook you up if I did. But I do have the Electrical Schem. for the '04, '05? I think, '06, '07 and I think that's it, I may be wrong. But this is the way it's done in every ignition module. There is no need for any (positive) pulse from the ignition to the coil other that to tell the coil when to discharge,(to fire plug).

2004 Models ONLY!

That is the same pulse the tach. reads. The '04 looks to only have a single fire coil (2 polls or connections), Yellow (Trigger) and Red (Power) wires. After all it turn to Green to go into the EHC and running all over the place inside, the it comes out of the EHC on 21 as Yellow and then to JST connectors 10 & 11 and then the Yellow goes into the tach.
:2thumbs::2thumbs:


Boy you guys are giving me a paper work "workout"! :lol:

You guys are going to keep me straight on this, I can tell! :roll:
 
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Hammitt

Hammitt

Member
Just got back from the dealer. Big Dog Motorcycles in Greensboro, NC.
Rode half of the way in the pouring rain and got my big ass soaked! Gotta love that big rear tire slinging water straight up and down your back.:D

Anyway, these guys are going out of business.
They replaced my tach ring for 50 bucks.
Not bad at all.
I did just buy this bike from them, but half price on the part and no labor ain't too bad. No warranty on the 04 of course.
Anyway, its working fine now.
I really enjoy all of the information, you guys know all there is to know about this stuff. Great site indeed!
Now for some dry clothes and a cold one:up:
 
T

TheDeadOne

Banned
Glad it fixed! :2thumbs:

From now on I guess you'll have to go to Raleigh?

Good Guys! :2thumbs:

Restaurant in same building, Steak Sub...AWSOME! :2thumbs:

Now get rid of the stripe down your back!..We can't have that kind of stuff around here! :lol::lol:

Good Luck! Be Safe! :2thumbs::2thumbs:
 
DRBarnhart

DRBarnhart

Insert title here...
TheDeadOne said:
There is no need for any (positive) pulse from the ignition to the coil other that to tell the coil when to discharge,(to fire plug).
Click to expand...
To trigger the coil (and make a spark) all you need to do is remove the ground (in this case the yellow wire) from the coil. And since we've already kind of hijacked this thread I won't go into why... :D

TheDeadOne said:
2004 Models ONLY!

That is the same pulse the tach. reads.
Click to expand...
Ah-ha, that's where we're seeing things differently! :eek:

TheDeadOne said:
The '04 looks to only have a single fire coil [actually that's dual fire - DRB] (2 polls or connections), Yellow (Trigger) and Red (Power) wires. After all it turn to Green to go into the EHC and running all over the place inside, the it comes out of the EHC on 21 as Yellow and then to JST connectors 10 & 11 and then the Yellow goes into the tach.
Click to expand...
And the wiring diagram I'm looking at for the '04 chopper shows 4 wires coming out of the ignition module. Three go to the EHC: red (power, pin 14), black (ground, pin 37), and green (tach signal, which goes in pin 20 then connects to a yellow wire coming out of pin 21 [also feeding RPM info the the EHC internally from there]) and one (yellow) goes directly to the coil for triggering it.

TheDeadOne said:
You guys are going to keep me straight on this, I can tell!
Click to expand...
And vice versa sir!!! :cheers:

I figure the more I know about these bikes the easier I can fix mine (when there's a problem) and help others to keep theirs running!! :2thumbs:

Dennis
 
BadBrad

BadBrad

2005 Pitbull
Damn guys!!!!!!!! I've got to go have a beer and read this again. I've had similar problems with my tach not working, then flashing crazy after getting wet. After it dries, all is well. I've recently sealed my EHC with Dielectric grease but need to try and seal off the tack so water does not leak into it. Did you also mention that the hand controls need to be waterproofed in some way? Been reading too many threads. Probably getting them mixed up. Thanks
 
BadBrad

BadBrad

2005 Pitbull
Thanks Dead. I'm still a new "double dog" owner since late February. The wife has a 2003 Mastiff and I have the 2005 Pitbull. Trying to learn as much as I can to keep money in my pocket working on these 2 bikes. Besides that, none of the techs know what you guys know. I spent most of this morning looking at the "exhausts" thread. Those are some sick ass pipes! Thanks again.
 
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