Died during a ride

MastiffBD

MastiffBD

New Member
Hello, I have a 2003 Mastiff and it died during a ride. I trailered it home and starting to try to locate the issue.
  1. No power to anything when the key is switched on,
  2. I pulled the ehc and tried to locate a hot wire, no ports on the connectors has any power? Is there supposed to be power there?
  3. I checked my ground wires and they are good.
  4. The small black box that has the red and yellow light only has the yellow light on.
  5. The mounted box? that has a connector on the front and a red light is not illuminated?
Where do I start?
 
knothead

knothead

Second Chance Customs
So I'm assuming the little black box you are talking about is the starter relay box. Take a pic and post the box you are talking about...actually take a picture of everything under your seat because I would like to see the ehc that on the bike.

It could be a bad starter relay which will cause nothing on the bike to have power, could be a ehc plug fuse etc...it could be a key switch or a wire...take a pic and post what you got and we will go from there
 
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Mikeinjersey

Mikeinjersey

Well-Known Member
MastiffBD said:
Hello, I have a 2003 Mastiff and it died during a ride. I trailered it home and starting to try to locate the issue.
  1. No power to anything when the key is switched on,
  2. I pulled the ehc and tried to locate a hot wire, no ports on the connectors has any power? Is there supposed to be power there?
  3. I checked my ground wires and they are good.
  4. The small black box that has the red and yellow light only has the yellow light on.
  5. The mounted box? that has a connector on the front and a red light is not illuminated?
Where do I start?
Click to expand...
First , Make sure your battery is healthy. It's possible your VR crapped out and the battery died or shorted out. A load test is the best way to know if your battery is in good shape. If all seems good these files may help you diagnose.
 

Attachments

Chong

Chong

U-238
knothead said:
So I'm assuming the little black box you are talking about is the starter relay box. Take a pic and post the box you are talking about...actually take a picture of everything under your seat because I would like to see the ehc that on the bike.

It could be a bad starter really which will cause nothing on the bike to have power, could be a ehc plug fuse etc...it could be a key switch or a wire...take a pic and post what you got and we will go from there
Click to expand...
03 Chopper,
I just had this (starter relay) take a dump on me .. The previous owner must have had a issue with it too because the starter trigger wire was already ready reouted (something I've never traced out) the relay out going big green wire was simply cut and is not connected to anything. But I lost all power .. it must be something like a double relay ? One for the starter selonoid and one for the "run" curcuit. Because the key switch wires come out of it too. With key on it triggers the run curcuit and powers up everything - ie: orange out going wire to the EHC. In my case the small red wire which is power supply to the key simply wasn't getting any power. I put a common 12v relay in to solve it . I have 03 wiring diagrams and neighter that or the BD relay has any diagram(s) about the inner workings of said relay.
 
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MastiffBD

MastiffBD

New Member
When I key it in only the yellow light on the starter box comes on and the red light in the metal piece used to light up red but doesn’t anymore.
 
knothead

knothead

Second Chance Customs
Starter relay is most likely the problem...the other silver box you are talking about is the ignition module...since you have no power no where is why it's not lighting up...the ignition module gets its signal from the cam sensor...but you need to check and make sure the ehc plug is making good contact because it can do the same thing as to not having any power...
 
Mikeinjersey

Mikeinjersey

Well-Known Member
MastiffBD said:
Battery is good
Click to expand...
I can't say I know the reason why but Lithium Batteries have a reputation for taking out EHC's . It makes no sense to me and I've never seen a reasonable explanation of how they differ (aside from CCA ) from the standard AGM . That being said, my bet is on the Deka ETX20L AGM just to be on the safe side. Great battery at a reasonable price with plenty of punch to run your bike.
 
Chong

Chong

U-238
This is a picture of the bad relay i took out of my 03 chopper.

I cut the small plug off for the 3 small wires grouped together. (Orange, red, green)

Note the phone key.. what I used to insert into the plug and test the above 3 curcuits.

So relay all hooked up other then the small 3 wire plug.

Using a 12v test light.

1st the small red wire does it test for +12v power . It should show power when the relay is connected to the battery. Your testing the plug end thats wired to the relay.

No power that's a problem.. This wire should show power at all times key on or off.

20250814_080444.jpg



No don't take fender off .
 
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Chong

Chong

U-238
If it tests bad .. plug the jump key into the Orange wire on that plug..

Use jumper wire and connect to 12v+.
Things may light up now.. as if key is on.
Note your start button will not work since that little green wire isn't hooked up.

If things don't light up you can jump 12v power to plug 4 pin 13.. on the EHC .
You can identify plug 4 pin 13 by looking at the #201 diagram Mikeinjersey attached above. This should light things up.. power up the EHC.

Further explanation. Plug 4 pin 13 is the same wire coming out of this relay. On mine it's the single orange(mine has a white stripe) wire that comes out of this relay. Follow that wire to the ECU , that's where you want to jump +12v to . There could be a inline single wire plug on that wire. I have revA and revB schematics.
Rev B shows the plug Rev A does not. If you have that inline single plug you simply unplug there and jump +12v to the end thats attached to the ECU.

For the record my bikes previous owner has replaced (spliced) in a new wire here. So mine doesn't have the inline plug.


The above tests cover the ignition side of the relay. There is a second function where it engages the starter.
 
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