Heated Gear & load on Electrical Sys. - Ducati.ms

dh1100 · Oct 27th, 2008, 8:35 am

Does anyone know how many amps could one draw safely before you put a load on the electrical system ?

I read in a post a few days back that somebody put 1 extra horn on their ride and could feel the ignition cut off if he hit the horn.

Between the jacket, pant & gloves I'm looking to draw 12 Amps.

GMP · Oct 27th, 2008, 9:37 am

Not sure but the total system output is 520W. There is no electric fan on the bike and it doesn't take much to run an EFI system. I'm running Gerbing jacket liner and gloves with no problem at all. You should be fine adding the pants.

There is more to that horn issue than just load. Could be HF noise introduced to the +12 V system from the horn. Without looking at things with a scope your just guessing.

lelenb · Oct 27th, 2008, 10:04 am

Slightly off topic but I using the horn output to power a relay off of the battery to run an air horn. It will also cause the power to cut out. I am betting that even if you unplugged the stock horn and hit the button it would cause a cut out. The horn wire is only 20 gauge at the most so I don't think it is a matter of current draw. I have not tried this, but I am pretty sure it is an ECU issue.

If I am correct you should have 38.8 amps total output at 13.4 volts, so I am sure there is enough capacity for your gear, though I do not know how much current draw there is for the electronics of the bike. Are you running a Canbus or just a relay? Also during the winter regulator is kept nice and cool so it should also be a benefit.

GMP · Oct 27th, 2008, 10:33 am

When adding relays, it is always neccessary to add a suppression diode across the coil to absorb HV spikes, unless one is built in the relay. Best is a solid state relay. I've had no horn or other electrical issues with my HM with either OEM or DP ECUs.

lelenb · Oct 27th, 2008, 11:35 am

Quote:

Originally Posted by GMP

When adding relays, it is always neccessary to add a suppression diode across the coil to absorb HV spikes, unless one is built in the relay. Best is a solid state relay. I've had no horn or other electrical issues with my HM with either OEM or DP ECUs.

Even with the stock horn if I pushed it like an idiot the bike would cut out. I found this out when I was riding with BillyD and i was trying unsuccessfully to get his attention with the stock horn it cut out slightly. I now have a cam ECU and it still does it. I do have a few block SSRs laying around I will swap one in and see if that makes a difference. I might just bypass the ECU for the horn and wire it straight to the relay/SSR.

GMP · Oct 27th, 2008, 12:36 pm

Quote:

I might just bypass the ECU for the horn and wire it straight to the relay/SSR.

That would be my plan. I don't think a horn needs an ECU for control. Perhaps there is a firmware issue in the ECU that causes this. Honestly I have never really held the horn button down long, just normal short beeps. Now I'll have to try and make it happen.

801 · Oct 27th, 2008, 11:42 pm

I'm trying to get caught up with the technical/electrical knowledge, so help me out a little.
1. Whats an SSR?
2. How is it the horn has anything to do with the ECU?
3. A little more detail (like in detailed instructions) about bypassing the ECU. Exactly what components would you need to do this and where would you get them, stuff like that.
4. For those running plug-in accessories like heated liners, can you rewind the stator like in a dirt bike to get more amps?
Thanks. -Kyle

Quote:

Originally Posted by GMP

That would be my plan. I don't think a horn needs an ECU for control. Perhaps there is a firmware issue in the ECU that causes this. Honestly I have never really held the horn button down long, just normal short beeps. Now I'll have to try and make it happen.

**BillyD** · Oct 28th, 2008, 12:18 am

Quote:

Originally Posted by lelenb

Even with the stock horn if I pushed it like an idiot the bike would cut out. I found this out when I was riding with BillyD and i was trying unsuccessfully to get his attention...

Hey, you honking at me...?

The HM has a partial CANBus implementation between the ECU and the Computer. If the horn is controlled by the handle bar switch through the Computer, then I would not be too surprised that using the horn for an extended time could cause the ECU to misfire.

In any case, I wired my grip heaters (36 amps) directly to the battery through a a Touratech TPS 15 CAN Bus Output Helper. Whenever the tail light is ON (which is whenever the key is turned on), the grip heaters get power; else they are turned off. Works perfectly.

The possible issue with heated clothing, however, is the TPS 15 is limited to a total of 15 Amps.

Max Current Per Gerbing's:

Jacket 7.8 Amps
Pants 4.5 Amps
Gloves 2.2 Amps
Socks 2.2 Amps

Total 16.7 Amps

BTW, I believe the HM has the same charging system capacity as the Multistrada, which certainly has enough capacity to power heated clothing.

Here's the TPS 15 installed.

The yellow wire on the right is from the TPS 15 and is spliced into the tail light connector.

dh1100 · Oct 28th, 2008, 7:56 am

BillyD, thanks for the images.
the TPS 15 would help.

much appreciated

GMP · Oct 28th, 2008, 9:36 am

Thats interesting, but you don't need it because the electric clothing has its own in-line controller. All you need to do is simply wire the coax power lead (supplied) directly to the battery + 12 and GND, it has an inline fuse. The power lead is hot all the time but it does not matter, as unlike Bill's grip heaters your clothing will not stay on the bike and possibly drain the battery. I run mine sticking out between the front of the seat and the tank cover, and when it gets warm and the Gerbings are not needed just tuck it under. It can also double as a battery tender connection.