Finally completely fried the ol' Thunderheart

[BigDogRick]

I have been relying upon an S&S (formerly Crane) H-4 ignition in the cone bypassing the old module. That worked for two years and about 3500 miles. But I have continued to rely upon the module to operate the low voltage start button, my turn signals, my headlight and highway lights, and, of course, my speedometer/odometer. yesterday as I took a ride about to enjoy my rebuilt carb and the fantastic Phoenix March weather at about 80 miles, as I sat at a light, I smelled what seemed like really foul exhaust fumes. I was glad when the light turned green and I left it behind me. Then, again at about 110 miles, I got the same whiff ... hmmmm. Then at about 125 miles my bike miss-fired big time and I smelled something electronic burn up. I kinda worried about an electrical fire but the smell dissipated quickly so I took my chances. Since I was still 7 miles from a place to shut down with assurance of cel signal, I kept going for about two miles. My two yellow blinker lights went on solid and my speedometer settled at 120 mph and she kept running. At that point I thought maybe the bypass H-4 was holding on and that I probably had no lights of any kind. I resolved to get as far as I could. A few seconds later, she shut down completely. I was able to call a buddy who came and got me and I hid the bike behind an old ironwood tree. When he got there, we headed to get my trailer and the rest was beer and enchiladas. Here's the suggested discussion. Since I absolutely love the H-4 performance and I have already rebuilt the ignition system, and I already have old-school Harley controls (albeit with low voltage wiring to the switches), I believe its time to hard wire the controls. Actually, that is a no brainer for me. But what about getting my odometer and speedometer back? I could live without the speedo, but the odometer is critical to anticipating gas tank refills, especially in the AZ/NM/NV desert. What would you do?

 

[Unsprung]

PM Badawg Bill or Mr Wright, both run old school wired bikes. Glad you got home safe, could've been worse...

 

[Th3InfamousI]

I have been relying upon an S&S (formerly Crane) H-4 ignition in the cone bypassing the old module. That worked for two years and about 3500 miles. But I have continued to rely upon the module to operate the low voltage start button, my turn signals, my headlight and highway lights, and, of course, my speedometer/odometer. yesterday as I took a ride about to enjoy my rebuilt carb and the fantastic Phoenix March weather at about 80 miles, as I sat at a light, I smelled what seemed like really foul exhaust fumes. I was glad when the light turned green and I left it behind me. Then, again at about 110 miles, I got the same whiff ... hmmmm. Then at about 125 miles my bike miss-fired big time and I smelled something electronic burn up. I kinda worried about an electrical fire but the smell dissipated quickly so I took my chances. Since I was still 7 miles from a place to shut down with assurance of cel signal, I kept going for about two miles. My two yellow blinker lights went on solid and my speedometer settled at 120 mph and she kept running. At that point I thought maybe the bypass H-4 was holding on and that I probably had no lights of any kind. I resolved to get as far as I could. A few seconds later, she shut down completely. I was able to call a buddy who came and got me and I hid the bike behind an old ironwood tree. When he got there, we headed to get my trailer and the rest was beer and enchiladas. Here's the suggested discussion. Since I absolutely love the H-4 performance and I have already rebuilt the ignition system, and I already have old-school Harley controls (albeit with low voltage wiring to the switches), I believe its time to hard wire the controls. Actually, that is a no brainer for me. But what about getting my odometer and speedometer back? I could live without the speedo, but the odometer is critical to anticipating gas tank refills, especially in the AZ/NM/NV desert. What would you do?

Rick speedo should run based on the transmission speed sensor. Can wire that in directly to your speedometer.

If you had an RPM gauge you'd have issues.

Check out this kit. Makes everything easy

http://www.namzcustomcycleproducts.com/product/ncbh-01-a-namz-complete-bike-harness/

Or easiest route is just replace that Thunderheart unit...up to you.

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[BigDogRick]

Rick speedo should run based on the transmission speed sensor. Can wire that in directly to your speedometer.

If you had an RPM gauge you'd have issues.

Check out this kit. Makes everything easy

http://www.namzcustomcycleproducts.com/product/ncbh-01-a-namz-complete-bike-harness/

Or easiest route is just replace that Thunderheart unit...up to you.

Sent from my 2PS64 using Tapatalk

Yeah. I am with you on the Thunderheart unit for path of least resistance. I have a bucket list thing I am pretty serious about. I want keep this ol' dog running until I have ridden it to all 48 contiguous states and mots of Canada's provinces and the length of the Baja peninsula. On the one hand, that Thunderheart worked flawlessly for 15 years. So maybe a new one will outlast the bike or me or both. On the other hand, a recurrent issue might best be tackled by a random mechanic in who-knows-where as I check off my bucket list, if its all old school. Thanks for the tip on the speedo. Gonna investigate that.

 

[TapioK]

Yeah. I am with you on the Thunderheart unit for path of least resistance. I have a bucket list thing I am pretty serious about. I want keep this ol' dog running until I have ridden it to all 48 contiguous states and mots of Canada's provinces and the length of the Baja peninsula. On the one hand, that Thunderheart worked flawlessly for 15 years. So maybe a new one will outlast the bike or me or both. On the other hand, a recurrent issue might best be tackled by a random mechanic in who-knows-where as I check off my bucket list, if its all old school. Thanks for the tip on the speedo. Gonna investigate that.

Something caused EHC to go, did you check the charging voltage? Just not to burn the next one...

 

[BigDogRick]

Something caused EHC to go, did you check the charging voltage? Just not to burn the next one...

Yes. I have replaced every other component several times in the life of the bike. Stator, coil, switch, battery, voltage regulator, all performing well. The EHC has been a very slow demise.

 

[FrankBDPS]

If the Thunderheart made it 15 years I would put one back in. Good luck and ride safe Rick.

 

[BigDogRick]

If the Thunderheart made it 15 years I would put one back in. Good luck and ride safe Rick.

Hard to argue.

 

[Mr. Wright]

I believe ThunderHeart still makes those old EHC's. I know you can still get the one's they used in the 03's. Not having been under the seat on an older Dog, I don't know what they used. I know on the 03, the EHC they used, lacked a starter relay, and it had an external component for that. I believe 03 was the only year for that one.

 

[BigDogRick]

I believe ThunderHeart still makes those old EHC's. I know you can still get the one's they used in the 03's. Not having been under the seat on an older Dog, I don't know what they used. I know on the 03, the EHC they used, lacked a starter relay, and it had an external component for that. I believe 03 was the only year for that one.

I have contacted Thunderheart for a part number. I think I will go that route if they still make it. If not, old school will be the safety net.

 

[FrankBDPS]

Shannon, don't bother looking under the seat on our bikes. It ain't there.

 

[BadDawg Bill]

Rick speedo should run based on the transmission speed sensor. Can wire that in directly to your speedometer.

If you had an RPM gauge you'd have issues.

Check out this kit. Makes everything easy

http://www.namzcustomcycleproducts.com/product/ncbh-01-a-namz-complete-bike-harness/

Or easiest route is just replace that Thunderheart unit...up to you.

Sent from my 2PS64 using Tapatalk

Good advice if you want to go old school. I would suspect you are half way there already. Good luck.

 

[Mr. Wright]

Shannon, don't bother looking under the seat on our bikes. It ain't there.

Yea I know, the thought ran through my mind about the time I hit post.

 

[Th3InfamousI]

I have contacted Thunderheart for a part number. I think I will go that route if they still make it. If not, old school will be the safety net.

I believe this is bad boy your looking for but thunderheart will confirm.

https://www.thunder-heart.com/shopexd.asp?id=289

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[BigDogRick]

I believe this is bad boy your looking for but thunderheart will confirm.

https://www.thunder-heart.com/shopexd.asp?id=289

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Thanks, Eric. This will help me communicate with them.

 

[BigDogRick]

Update: we are narrowing down the issues. The event fried the brand new battery. Replaced. The single pole relay that acts as a system master fuse is good. Power is getting to the EHC. Ground is good out the other side. No blackening or evidence of burning up in the EHC. The bike responds to the end-around ignition wiring but will not fire (so the starter relay that controls the start button within the EHC is still good). All the wire harness appears to be good. Have a Thunderheart tech available via phone - hopefully we get some dialogue today. We have confirmed that the 4250 is the part number - so the pdf owners manual provided on the Thunderheart website is very useful. No light or speedometer or LED light response to the "key on" position - except a single flutter in one LED once - until the single pole relay opens up in distress. Still hunting.

 

[Th3InfamousI]

Update: we are narrowing down the issues. The event fried the brand new battery. Replaced. The single pole relay that acts as a system master fuse is good. Power is getting to the EHC. Ground is good out the other side. No blackening or evidence of burning up in the EHC. The bike responds to the end-around ignition wiring but will not fire (so the starter relay that controls the start button within the EHC is still good). All the wire harness appears to be good. Have a Thunderheart tech available via phone - hopefully we get some dialogue today. We have confirmed that the 4250 is the part number - so the pdf owners manual provided on the Thunderheart website is very useful. No light or speedometer or LED light response to the "key on" position - except a single flutter in one LED once - until the single pole relay opens up in distress. Still hunting.

Looks like your on the right track!

Just a couple suggestions...since I'm at work and much rather be working on bikes..ha


Have you confirmed if you have power going to the Cam sensor. I think those cranes have an LED on it? So that should be easy quick tell.

Then see if the coil is getting power.

Should be able to tell ya if the EHC is feeding anything? Or Did you power your crane directly off battery? Maybe fried the ignition when battery went?.

Wondering if VR shit the bed and took the battery with it and some other stuff. Thats what happened to me unfortunately.

Good luck on the hunt there.



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[Th3InfamousI]

Also check your headlight...could be grounding out on the bucket or something. Do you have a LED in there or halogen?

Sounds like something is grounding out which is causing the EHC relay to shut things down.

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[BigDogRick]

Looks like your on the right track!

Just a couple suggestions...since I'm at work and much rather be working on bikes..ha


Have you confirmed if you have power going to the Cam sensor. I think those cranes have an LED on it? So that should be easy quick tell.

Then see if the coil is getting power.

Should be able to tell ya if the EHC is feeding anything? Or Did you power your crane directly off battery? Maybe fried the ignition when battery went?.

Wondering if VR shit the bed and took the battery with it and some other stuff. Thats what happened to me unfortunately.

Good luck on the hunt there.



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Eric,
Checking the transmission sensor. I think mine preceded the "programmable" one with the LED and speedometer adjustment capability. The VR and coil are next.

 

[BigDogRick]

Also check your headlight...could be grounding out on the bucket or something. Do you have a LED in there or halogen?

Sounds like something is grounding out which is causing the EHC relay to shut things down.

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Now that could be: the highway lights are suspect. Passes through a simple toggle on the upper fork nacelle.