In preparing for a GPS install, I fished out the ACC 1 and 2 wires from under the seat on my '16 1290 R. Sure enough, the ACC1 10A circuit is always on and shows 12+V with the bike turned off and the ACC2 shows no juice. When I turn on the bike, it get an instant 12+V on the ACC2. I start the bike and it continues with no glitch just like I'd expect. But when I turn the bike off with the key, the ACC2 voltage drops not to zero but to about 8V. It stays there for a while and then finally drops off to zero.
On my BMW CANBUS bikes, it's normal behavior for the bus to stay hot at 12V for a minute after I turn the bike off. It makes me think that the KTM controller works similarly but what I'm puzzled about is why I'm not seeing a full 12+V on the ACC2 connection. The bike is new with less than 300 miles on it and the battery shows 12+V on it. Why would the ACC2 voltage drop when so significantly when it goes into this "countdown to off" mode? Something like a Gerbing controller probably wouldn't care but I'm a little worried what it'll do to any 12V accessories (like my zumo GPS) when they see an 8V supply.
So, what's up with that?
Twist
2016-06-27 11:30:00 UTC
Twist
2016-06-28 20:31:00 UTC
[crickets....]
No one here knows anything about the ACC2 circuit behavior? Specially, I'm interested in why there's a voltage drop when the ignition goes off and is it a specific designed behavior how long it stays on before deactivating? Does it matter if there's a draw on that circuit when the bike is turned off as to how long it stays on?
Someone here must have this information? If not, I'll post up my GPS install description on the ACC2 circuit and try to characterize it's behavior for posterity.
No one here knows anything about the ACC2 circuit behavior? Specially, I'm interested in why there's a voltage drop when the ignition goes off and is it a specific designed behavior how long it stays on before deactivating? Does it matter if there's a draw on that circuit when the bike is turned off as to how long it stays on?
Someone here must have this information? If not, I'll post up my GPS install description on the ACC2 circuit and try to characterize it's behavior for posterity.
Twist
2016-06-29 15:09:00 UTC
Don't have the schematic here in front of me atm but my recollection is that ACC2 is controlled by an SSR (solid state relay) in the ECU. SSR's typically have a small leakage current when off. If you have a normal voltmeter, the small current draw of the meter will pull the 12V down to something less, like 8V in your case. After 1 minute, the ECU shuts off everything. If you have anything with a "normal" current draw attached to ACC2, you will see 0V there as soon as you turn the key off. So no need to worry about low voltages messing up things attached there.