EHC OR NOT?

Mattlock

New Member
Alright guys, please be easy on me i'm new to the Big Dog Biker ways. I bought a used 07 chopper, and i'm having some weird electrical issues. First off my odometer and mileage wouldnt change when i tried to toggle them, then the tach lights started pulsing after a couple months, and now my speedometer wont work after i pass 30mph, and my tach lights wont come on at all. so basically my whole instrument cluster shuts down. Ive read alot and the only thing I can come up with is the EHC module is bad?? I took the seat off and when i hit the start button a red light comes on. when its idling an orange and blue light pulse in sync with the engine firing. If anyone can help me diagnose my issues i would appreciate it! ps, if it is an EHC module how much is one, and how hard is it to install?:confused::confused:
 

1BADK9

Limited Edition Member
Thanks for the reply. Get rid of the EHC or the bike?
Just the EHC, I'm sure you'd like to hold on the bike a little longer. :roll: but really take a good look at all electrical connectors, at speedo, EHC, and battery make sure it's not something simple like a poor connection.
 

KnotSo

Admin
Staff member
The battery should always be the first thing to check. Put a volt meter to the battery and get some readings..:cheers:.
KISS, keep it simply simple, check the easy stuff first
 

Brew

Troop Supporter
Might want to pull your speed sensor and clean it also! Sometimes crud may build up on it and cause it not to pick up. That could be the cause of your speedo not working after 30 MPH. Give it a try...
 

BigDogBro1

Made in the USA
The EHC doesn't have much to do with the speedo other than providing +12v power control.

It's not always the EHC and too many people here seem to say it's the culprit before offering any real helpful advice. Not that it has happened on this tread. It's a great product when installed to replace a failed EHC, but it won't fix all bad wire connections, the battery or speedometer. After you elliminate all other possibilities then you could make a more logical choice.

Knotso's battery suggestion is a great first step. You should have a minimum of 12.6 to 12.8 volts across the terminals off the charger an hour or more.

Disconnect the battery then the EHC harness connectors and clean and fill the EHC connectors with fresh dielectric grease.

Before you go out a spend $500+ dollars and 6+ hours labor for the Wire+, you need to make sure you have good clean connections in the gauge head. The speedo has a three wire connector for power, ground and signal from the speedo sender on the trans. Poor power connections will cause erratic operation. Sounds like a speedo unit due to no trip mileage button working and other gauge connection related problems.

The annunciator board (tach and other LEDs) also have power, ground and many other signal wires. The connector could be loose, bad wire, cracked board, water damage, or a host of other possibilities.

These dogs don't like the water. So when you wash them...keep the hand controls dry or covered with a plastic bag and don't power wash any connectors. You need to go through all harness connections and clean and fill with fresh dielectric grease as a maintenance item.

Hope this helps! :cheers:
 
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Slick-Dog

Active Member
Well that answers my question about "loose wires" that I posted!!! So many nightmares about the EHC is driving me Fn nuts... Thanks BigDogBro1 :up:
 

RRRUFF

Well-Known Member
Great advise here start with the simple things first. As stated above check your connectors and check for broken wires. Replacing the ehc is not going to fix anything else that is wrong. One other thing I would add is that a friend had the same problem with his speedo and took it back to the dealer under warranty and they said they had to flash the speedo/ehc and he hasn't had any problems with it since. As BigDogBro said check the circuit board in the speedo and check it at the bottom. As water gets into the speedo it will settle out in the bottom on this circuit board and will cause corrision. If so clean it up and what I did was put a coat of RTV on the board in that location to protect it. And again as stated above these dogs don't like the water.
 

Mattlock

New Member
man thanks for the awesome feedback. rode my bike to work yesterday, tried to start it and the EHC started smoking. it melted my positive battery post off the battery! I think I may have a nightmare on my hands
 

outdoorsman26

Well-Known Member
like bigdogbro1 said you prolly have a "wire" problem and its not the ehc!! now that the "wire" problem has fried your ehc you now have to spend $500+ 8hrs installing the wirs plus and you should still chec your entire bike for a worn thru wire!! there is sumthing shorting out and ist going to keep shorting out til you find it!!! get a hold of jake http://lowdownchopshop.com/big-dog-e...le-wp-374.html he will set you up with the wires plus!! good luck and god bless
 

outdoorsman26

Well-Known Member
there are guys on here have built and worked on these bikes for yrs!! just grab a beer and chill, and take a look...you can buy a service manual for your bike and it will tell you how to take your whole bike apart and it has pictures!! if you still dont get it just ask on here I will guarantee there is someone on here that has had the same problem!!! get the manual and read it!!!
 

Shane

Active Member
If you let the smoke out of it it's done....i have an EHC from an 05....will sell it but you need to find the reason the smoke got out first.....or you will let the smoke out of this one....
 
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