2003 BDM to ThunderHeart Module Conversion

All,
I have been getting a lot of emails lately regarding 2003 BDM EHCs. I do not know it to be true but some of these guys have told me the 2003 EHC is on back order till Sept. I have helped about 4 people rewire their 2003 BDMs to a ThunderHeart module ASM4250 (Thunder Heart Quality Products).

A little history on the 2003 EHC. BDM used the Thunder Heart EHC for a few years up until 2002. In 2003 they went to a proprietary EHC made by a local company. The EHCs were basically the same however besides what I noted the main difference between the EHCs is the relay. On the BDM EHC the relay is for the headlight, on the Thunder Heart module the relay is for the starter solenoid. Both EHCs pass high (relative term) current thru the handlebar controls. If you have or plan to switch hand controls to aftermarket or new BDM controls you will need to purchase a module to convert the signals to low current so you do not damage the hand controls.

Attached you will find basic instructions on how to make the conversion from a stock 2003 BDM to a Thunder Heart ASM4250 module. Take your time, read thru the instructions it is really an easy conversion. I am not sure the part number but BDM used to sell a service kit for the 2003 that had a pin extraction tool in it. If not the connectors used are Tyco (Amp) Mate-N-Lok series rectangle connectors. You may be able to get a universal type extraction tool from radio shack. If not look online to Digikey.

I could not post the BDM schematic on this site due to size constraints and possible copy right rules so I would recommend getting one from your dealer, BDM Service manual or maybe some out there has something they can email to you.

Hope this helps you guy/gals out and gets ya back on the road. Don't let it intimidate you, it really is as easy as it sounds. :flag:
 

Attachments

S

SF180A

Guest
Thank you Mike,

This was a great post.

I have an 03 Mastiff that has come down with electrical problems. The Tach, Speedo, plate light, and rear running lights stopped working all at once. I am now in the process of trying to find a good bike repair shop in Virginia Beach to look at it.

:cheers:
Brent
 
Brent,
All of those components you mentioned get power from the same solid state fuse inside the EHC. First thing I would look for is a short to ground at any of these locations. Disconnect battery and use a continuity meter (or ohm meter) to determine if you have continuity (or essentially zero ohms) from the red wire to ground. If you do start tracing the wires till you find the problem. You can isolate your EHC to make sure it is not something internal. if you do find a short remove the front harness connector and the 13 pin main connector and see if you still have continuity to ground. If you do the problem could be in your EHC. Check for continuity in the EHC from pin one of front harness connector or pin 9 of the 13 pin connector to to ground (pin 1 of 13 pin connector).

Component failure could cause the same problem. You can check for a component failure buy disconnecting all of those one at a time and see if you get power back to the rest of them when you disconnect something else.
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Brent,
All of those components you mentioned get power from the same solid state fuse inside the EHC. First thing I would look for is a short to ground at any of these locations. Disconnect battery and use a continuity meter (or ohm meter) to determine if you have continuity (or essentially zero ohms) from the red wire to ground. If you do start tracing the wires till you find the problem. You can isolate your EHC to make sure it is not something internal. if you do find a short remove the front harness connector and the 13 pin main connector and see if you still have continuity to ground. If you do the problem could be in your EHC. Check for continuity in the EHC from pin one of front harness connector or pin 9 of the 13 pin connector to to ground (pin 1 of 13 pin connector).

Component failure could cause the same problem. You can check for a component failure buy disconnecting all of those one at a time and see if you get power back to the rest of them when you disconnect something else.
NT, I'm glad your back cause I didn't understand one bit of this!!! :lol:

When you re-wiring my bike? :D
 
I do better with electrical circuits that I do clear sentence structure. Sorry bout that. I figured if people get confused they can always post more questions and I will try to be a bit more clear. I don't have much time now a days to get on the computer for personal time so when I do I have to type fast and hope at least 1/3rd of it is clear :job:

FedEx me your bike and I'll take care of it for ya. :2thumbs:
 

kiwi

Active Member
great post night train
do you have anymore pics of your night train , i can only find a few and it looks great and great paint job
 
S

SF180A

Guest
Thanks again Mike,

I had a friend stop by who works for Ford and asked him for some help tracking down the short. After I took the seat and dash panel off showing him the ECH and battery terminals, I handed him my OHM meter and he then said he needed the wire diagram. so after a few "hog starring at a wristwatch glances" and more "fuck if I know", I decided to return to my beer drinking and will continue to look for a local bike mechanic that understands the ECH and related electrical problems.

I know my way around C-4, door kicking, and other related skills, but this ECH/electrical stuff is kicking my ass!


Brent
:cheers:
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Thanks again Mike,

I had a friend stop by who works for Ford and asked him for some help tracking down the short. After I took the seat and dash panel off showing him the ECH and battery terminals, I handed him my OHM meter and he then said he needed the wire diagram. so after a few "hog starring at a wristwatch glances" and more "fuck if I know", I decided to return to my beer drinking and will continue to look for a local bike mechanic that understands the ECH and related electrical problems.

I know my way around C-4, door kicking, and other related skills, but this ECH/electrical stuff is kicking my ass!


Brent
:cheers:
Brent, most of the wiring diagrams are posted in the Tech section. :D
 

skipmozilla

Member
Had all the same things quit woking on the OL's 03 Bulldog, since that EHC was the second one (a year and a half old) I went with the Wire-Plus.
Wish I had read your post a month ago, I think the ThunderHeart would have been cheaper and a better fit.
 
WP is a good unit...you are up and running. Hard to put a price on being able to ride vs looking at it collect dust in the garage.
 
S

SF180A

Guest
I found the 07 wire diagram in the Tech section, but not one for an 03. How close is this to an 03? Does anyone have and old wire diagram they could share?

I am going down to a custom bike shop located across the NC/VA border, hoping to get my bike in tomorrow for a check to see if it is just a short, loose wire or ECH, then go from there.

Thanks for all the help,

Brent
:cheers:
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
I found the 07 wire diagram in the Tech section, but not one for an 03. How close is this to an 03? Does anyone have and old wire diagram they could share?

I am going down to a custom bike shop located across the NC/VA border, hoping to get my bike in tomorrow for a check to see if it is just a short, loose wire or ECH, then go from there.

Thanks for all the help,

Brent
:cheers:
Courtesy of Bikers Dream on this thread. A bit hard to read but maybe you can blow it up.
http://www.bigdogbiker.com/forums/help-wanted/15550-2003-mastiff-wiring-diagram.html
 
S

SF180A

Guest
Thanks Ray,

I am in the process of printing this diagram up, and will take it with me tomorrow to see if this will help track down the electrical gremlins.

Ride safe,
S180A/Brent
:cheers:
 

Tank

Member
We have a WP retrofit kit in stock that mostly just plugs in here. Although it looks like the 01-2 Thunderheart kit, the 03 is a unique animal from any other Big Dog.
 

suuckerpunch

New Member
NIGHT TRAIN . IM NEEDING A LITTLE HELP . HAVE 03 CHOPPER SWITCHED ECM TO THUNDER HEART ECM. EVERYTHING WORKS EXCEPT THE STARTER SWITCH IN RIGHT HANDLE BAR CONTROL. IF I JUMP STARTER FROM BATTERY BIKE STARTS AND RUNS . ONLY THING NOT WORKING STARTE SWITCH . IT WORKED WITH THE BDM ECM . ANY IDEALS WOULD HELP. I AM A BIKE MECHANIC . SO IVE BEEN THROUGH GROUNDS . NO CHANGE . I HAVE EXHAUSYED ANY IDEALS I HAVE HAD . NO CHANGES.
 

Samson

New Member
This ASM4250D...does this replace the BDM module BD4030-1B? or was there another BDM EHC...used on the 03 Mastiff? I pulled mine today to find it full of gas that had leaked from the air vent on the tank (hose was missing) its a wonder Im still alive...rode it 3 or 4 times before the headlamp stopped working. One lil spark from a short and I woulda been roasting my nether regions on an open fire. The module is working halfway but it has to be the module breaking down internally....a relay or something. Been trying to find a replacement module for it but the Thunderheart module does not list replacement numbers, and there are no BDM modules to be had right now. All ebay has are wire plus kits.
 
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