When to Replace EHC

bryant1609

Active Member
Can anyone please give me an idea when you should replace your EHC? I have a 2007 K9 with about 15K on it. I never had the EHC flashed, and every now and than the Left Signal light would stop working, or the Tach and Speedo wouldn't work for afew. Explain; this I was riding and stopped back home form about 2 hours before going back out. When I went to start the bike it started right up but no power to the Tach or Speedo. I tried turning it off and on a few times but still nothing. So I got on and rode it the way it was and after going about a mile the Tach and Speedo came on. Does this mean I need to get the Flash Upgrade or replace the EHC totally with the new PDM from BDM (EZ Installation) or get a Wireplus instead (Pain in the BUTT installation)?
 

erldawg

Guru
I'd start looking at all the connectors. Pull them apart and put in some dielectric grease in each one. Sounds to me like a bad connection somewhere. Look for wires rubbing on frame or anywhere else causing bare wires etc. If all that fails then onto the wire plus and or BDM EHC replacement your choice.
 
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bryant1609

Active Member
This wasn't the first time this happened, but after seeing all the post about replacing the EHC I was wondering if this is the start of something happening to it. I pulled the battery out and made sure nothing was touching anything and reconnected the battery. Everything appears fine at this time. But just the other day everything was working but the Left Signal Light. Which was why I pulled the battery and reconnected everything. I'll try the dielectric grease.

Hey you live in Central Islip NY, we should be riding together, I live in Valley Stream, NY
 

erldawg

Guru
I would follow the wires back to or from the left turn signal. They may be ground out somewhere.
Disconnect connections to EHC and make sure it's clean and has the dielectric grease like I recommended above. If the EHC was going I would think it would just die all together.

I'm in upstate NY ... Syracuse area... Land of snow and grey skies....
 

woodbutcher

Mr. Old Fart member #145
Staff member
i've got an '07 and i KNOW my battery is on it's last legs. always on a tender but when i first crank, the speedo goes through its cycle and the tach works but the speedo/odo does not register. i always ride a mile or two and stop, shut it off, and restart it. then the speedo/odo work like they are supposed to. my thought is it is just a weak battery. jason, the BDM mechanic, was down at carl's speed shop during dayton a few years back and tried to flash my EHC but apparently some of them had some corruption about them and would not flash. so i ride it until it quits.
 

bryant1609

Active Member
i've got an '07 and i KNOW my battery is on it's last legs. always on a tender but when i first crank, the speedo goes through its cycle and the tach works but the speedo/odo does not register. i always ride a mile or two and stop, shut it off, and restart it. then the speedo/odo work like they are supposed to. my thought is it is just a weak battery. jason, the BDM mechanic, was down at carl's speed shop during dayton a few years back and tried to flash my EHC but apparently some of them had some corruption about them and would not flash. so i ride it until it quits.
Yes I had the problem too for awhile than changed the Battery and the Volt Regulator and that went away. I'm on my third battery with about 15K on the bike. As soon as I get off the bike at home it goes right on a Tender. Trying to find a good Roadside Assistent company now so I don't worry about getting stuck out there somewhere and no way to get the bike back home cheaply.
 

BWG56

Guru
My speedo did the same thing and the dealer tried to flash it but the EHC would not take the update. They replaced the EHC with a newer one (meaning newer than what my 07' came with) and did the flash and it hasn't done it since. The speedo goes through its diagnostic after the bike is running so there is now power being pulled from the battery by the starter.
I also just replaced my battery after 4 yrs even though it would still start the bike, but the new battery spins the motor much faster during start up.

Try letting the speedo do its thing before you hit the starter, and see if that makes a difference.
 

bryant1609

Active Member
My speedo did the same thing and the dealer tried to flash it but the EHC would not take the update. They replaced the EHC with a newer one (meaning newer than what my 07' came with) and did the flash and it hasn't done it since. The speedo goes through its diagnostic after the bike is running so there is now power being pulled from the battery by the starter.
I also just replaced my battery after 4 yrs even though it would still start the bike, but the new battery spins the motor much faster during start up.
If I recall, someone told me if my EHC had a USB connection that it was the newer EHC and didn't need the Flash. Which is why I never got it done. Can I just go to any Big Dog Service and have the Flash done? ANd what sure I pay for this???
 

erldawg

Guru
Then you didn't ride this weekend, must have been too cold up there.
Friday was in the high 50's, Sat n Sun mid to high 40's felt like a heat wave after this past winter. I heard plenty of bikes out but I did not ride. Bike is still sleeping and this week the temps are going in the wrong direction. So not for a few weeks yet....
 

JRosales

Member
you should replace your EHC As soon as you get a Big Dog...Not only your EHC, the entire electrical system.... This is by far the weakest part of a BDM.
 

bryant1609

Active Member
Battery change without a doubt.......
Battery didn't appear to be an issue. I was able to turn the bike 4 to 5 turns in a row and each time it turned over without a problem. Just the Tach and Speedo didn't get any power. Than rode aboout a mile and everything came on like nothing happened. This battery is only about 5 months old too. Brought it near the end of the season last year.
 

woodbutcher

Mr. Old Fart member #145
Staff member
If I recall, someone told me if my EHC had a USB connection that it was the newer EHC and didn't need the Flash. Which is why I never got it done. Can I just go to any Big Dog Service and have the Flash done? ANd what sure I pay for this???
the late '06 early '07's with the USB are the ones that need to be flashed. you can't flash the ones with the round port.
 

BWG56

Guru
If I recall, someone told me if my EHC had a USB connection that it was the newer EHC and didn't need the Flash. Which is why I never got it done. Can I just go to any Big Dog Service and have the Flash done? ANd what sure I pay for this???
If the flash was done then the speedo should calibrate before you hit the starter and after its running. If it only calibrates once you need the flash and I would think the dealer would do it for nothing, mine did but it was still under warranty and I did buy the bike from him.

Mine did not have the USB port and thats why they replaced it, but they left me under the impression if it had the USB all they had to do was reflash. So I had to go back after they ordered an EHC in.
 

Ratman

Active Member
It is my understanding that most of the 07's did not come with the correct plug to flash. My 07 Mastiff had the "old" style plug...and the EHC was changed out at about 750 miles to the new EHC so they could flash the speedo. I have not had one bit of trouble with my EHC...and bike has 5000 miles on it. I do have a WP kit to install in the next few weeks.

I would check the battery first before changing anything.
 

bryant1609

Active Member
It is my understanding that most of the 07's did not come with the correct plug to flash. My 07 Mastiff had the "old" style plug...and the EHC was changed out at about 750 miles to the new EHC so they could flash the speedo. I have not had one bit of trouble with my EHC...and bike has 5000 miles on it. I do have a WP kit to install in the next few weeks.

I would check the battery first before changing anything.
I check the battery with Volt Meter and it's fine. Battery is only 5 to 6 months old and stays on a Tender anytime the bike is in the garage. This is why I don't feel it's the battery causing this issue. I also checked the Regulator which I replaced last year. When the bike is running it's at about 13.89 at the battery, On the Tender it about 13.60 at the Battery, Battery by itself is about 13.50. The battery is still under warrenty too.
 

Ratman

Active Member
When I purchased my bike NEW...it had the OEM in it that I replaced with a new Interstate battery just a few months after bike purchase. The NEW Interstate battery had a bad cell in it and had to be replaced a week later. I kept it hooked to a tender as well. That battery left me beside the road...the first time for me in about 40 years. Speedo and tach would do crazy stuff.
LOAD TEST.
 

bryant1609

Active Member
When I purchased my bike NEW...it had the OEM in it that I replaced with a new Interstate battery just a few months after bike purchase. The NEW Interstate battery had a bad cell in it and had to be replaced a week later. I kept it hooked to a tender as well. That battery left me beside the road...the first time for me in about 40 years. Speedo and tach would do crazy stuff.
LOAD TEST.
Unstood but this isn't the first time my Tech and Speedo and Left Signal Light have done this. But due to the fact I've been on the Forum more as of lately and reading all the stuff about the EHC I'm now realizing that this could be the issue why the Tach and Speedo and Left Signal Light was doing this before.

To be clear this was happening before I changed the Battery. It just doesn't happen enough that I looked at it as a problem at the time.
 
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