Troubleshooting speedo issue, need a little help

[Moespeeds]

This 2005 chopper I'm working on had speedo issues, his speedo would randomly not working. It was a white faced beat up piece of junk. I got him a black faced from BD parts kingpin on ebay, reman I'm assuming. Now the speedo needle is dead. Tach and all other functions are fine. When I power up, the needle swings up to about 80mph and back. Odo reads zero. The connections under the tank are a little fishy, but physically look ok. Just seem a little loose. Does the speedo needle swinging on power up indicate a connection to the sensor on the tranny or just that its getting power?

 

[chacha]

Just that she's got power and setting the stops for the servo-motor. Do the backlight LED's stay lit?

 

[Moespeeds]

Yes. I wrote this post sitting in the bar, and when I went out and rode the bike, it was working fine. I'll keep an eye on it.

 

[Raywood]

Yes. I wrote this post sitting in the bar, and when I went out and rode the bike, it was working fine. I'll keep an eye on it.

Sounds like a weak power up cycle. That is why all the new ones now go thru power up twice. To much going on during startup so now they cycle again when the battery/altenator has full power.

Check and ensure your battery is strong enough. May need replaced. Hopefully the guy is keeping it on a tender all the time. He also should have the new speedo bracket that is wide at the base.

 

[lee]

The connections under the tank are a little fishy, but physically look ok. Just seem a little loose.

that seems less than ideal as well

 

[dog1]

btw: is it normal... when Im cruising at 60-70 or so my speedo needle vibrates back and forth like from the road conditions being bumpy and not an electrical problem. thanks

 

[BigDogBro1]

Yep!

 

[Moespeeds]

Ray tell me more about the power up problem. I tested it a little more today, and if the speedo works, it keeps working. If it doesn't work from start up, I power off with the key, and power back up and it gets going. New 310CCA battery. Speedo came from BD PartsKing last week, its a black face. All other functions seem to be working fine.

 

[Night Train]

You are having the issue seen by others and what prompted a software up grade in the EHC to fix it. The EHC is not to blame in this case, the processor autometer used in the newer speedometers are more susceptible to low voltage conditions. BDM found that a software upgrade in the EHC the would reset the power-up circuit after the starter button has been released will fix the problem. If the 2005 chopper you are working on has had the newer EHC installed you are in luck, simple software update will fix your problem. Look at the EHC that is installed. If it has a USB connector on the diagnostic dongle it is the newer EHC, if it is a round black plug we are going to have to work around the problem. Let's start by seeing what EHC you have. If it is the old one I'll give you some ideas on how to work around it.

 

[Moespeeds]

It's a round black plug.

 

[Night Train]

The black plug EHC does not accept software upgrades. This means to make sure your speedometer stays working that battery has to be near full charge at all times but that is not always easy or 100%. The other options is to put a normally closed momentary switch on the power or ground side of the speedometer. If the speedometer causes you problems you push the button and it will reset it. The speedometer and sensor pull about 150mA, if you get a button that can handle 250-500mA you will be good. You can do this with some delay relays so it would be automatic, this will cost a little more and take more to wire in. If you want to do this let me know and we can get you hooked up.

 

[Moespeeds]

How is it that I never heard of this, or saw this problem on another bike? The bike's owner has zero mechanical skill or comprehension, so I'd rather not add any switches. Could I get a relay that will break the connection when it receives a 12v signal? I could wire this into his horn circuit, so if the speedo doesn't work, he hits the horn to reset it?

 

[Moespeeds]

What do you guys think of putting a starter relay on the speedo power, activated by the horn? A HD starter relay has a normally closed center post, which kills power to the headlight when activated. I could wire the speedo through this, and activate the relay with the horn?

 

[DRBarnhart]

BDM found that a software upgrade in the EHC the would reset the power-up circuit after the starter button has been released will fix the problem.

How about adding a small relay with the speedo power going through the normally closed set and the relay coil controlled by the starter solenoid wire?

That way when you hit the start button the speedo's power would be cut and when you released the start switch power would return to the speedo. There wouldn't be any user input required which seems like it would meet Moe's requirements.

Isn't this pretty much the same thing that Big Dog has done in the EHC?

Dennis

 

[Night Train]

Don't know why DBR's suggestion wouldn't work.

 

[Moespeeds]

Sounds good to me DRB, thanks! Anyone know what model/year Harley will have the correct relay? When I call a dealership, they know nothing about the relay itself, only what models it will fit.

 

[Raywood]

Boy..... You guys are getting way to complicated for my simple brain to fathom!!

 

[Night Train]

Any 5-Pin relay you can pick up at a local parts store will work. Attach pin 86 to ground, 85 to starter solenoid signal, Pin 30 to speedometer power, 87a to speedometer power from EHC. You could also open the ground side of the speedometer if you want instead of power. 87a is the normally closed pin. When you hit the starter the relay coil will energize. This will removed power from 87a and connect 30 to 87. 87 will be a no connect.

Just make sure you get a relay and not a flasher module. If you look around you can probably find the small micro relay that will take up less space. The relay needs to carry less than 1amp. You could even use a smaller one from radio shack.

 

[Moespeeds]

All 5 pins are normally closed, or will I need to ask for one specifically?

 

[DRBarnhart]

Do you mean if you put a meter (set to continuity) on pin 30 and 87A you get an open?

Dennis