997 cdi short circuit fail state

[reaper687]

anyone ever ran into this issue on the 997 you can unplug everything and just plug in the cdi and its shorts the main fuse. krash in the diagnostics breakdown says its a short circuit fail state.
all that happen is i started my ski with out plug boots on and then pop hasnt ran since then keeps shorting the fuse. wondering if there is a way to get it out of the fail state mode.

 

[Jcary85]

you’ll need to find what’s shorted to ground. Start by disconnected the coils. Idk what year you have but there’s an adapter between harness and ECU that is all non tinned wire and will probably be heavily corroded. The bottom line is you have to find the short. It’s not like a GFI you reset or something.

 

[reaper687]

its a 19

 

[JC-SuperJet]

So you didn't ground the Spark Plug Wires?

The 30 thousand volts have to go somewhere!

That means that the Coils and CDI couldn't shoot their loads and got very hot. The Ignition Coils probably survived, but the CDI internal Diodes (electrical check valves) probably got fried. The CDI internal Capacitor might have gotten fried also.

The CDI receives Voltage from a Battery or a Stator Charging Coil, then kicks ups the Voltage to about 600 Volts and sends it to the Ignition Coil, where the Ignition Coil steps the Voltage up to 30 kilo-volts and sends that load to the Spark Plugs...

You might can rig an MSD Enhancer or Zeeltronic CDI to your E-box and test. This will tell you if the Krash CDI is good or bad.

 

[WFO Speedracer]

I have zero experience with these whatsoever but I do have experience with Seadoos , when the MPEM direct shorts to ground on those MPEM's it is because of an $8.00 diode, if you can locate the diode without destroying other components in the process you can fix those fairly easily , I have repaired a few of those .

Basically what Jscary said , unplug everything except the power lead and the ground lead if it still blows a fuse it probably has a blown diode somewhere.

Diodes are fairly easy to check, they flow current one way only , they act just like a backflow preventer on a household water system, if you check resistance and it has resistance one way , then you reverse the leads on the meter and check it again , if it shows anything the opposite way it is bad.

 

[reaper687]

so i did a bu.nch of testing this morning and i found the cdi has power on the ground side of coming out of the cdi so from what i can figure something did short internally i am gonna try to pull it appart and see what i can do. so its pretty much what you said wfo speedracer it shorted to the ground side of the cdi.

 

[Jcary85]

So you didn't ground the Spark Plug Wires?

The 30 thousand volts have to go somewhere!

That means that the Coils and CDI couldn't shoot their loads and got very hot. The Ignition Coils probably survived, but the CDI internal Diodes (electrical check valves) probably got fried. The CDI internal Capacitor might have gotten fried also.

The CDI receives Voltage from a Battery or a Stator Charging Coil, then kicks ups the Voltage to about 600 Volts and sends it to the Ignition Coil, where the Ignition Coil steps the Voltage up to 30 kilo-volts and sends that load to the Spark Plugs...

You might can rig an MSD Enhancer or Zeeltronic CDI to your E-box and test. This will tell you if the Krash CDI is good or bad.

Just FYI, if it’s megasquirt based (I believe this one is) it’s not CDI. It uses smart coils from a mercury outboard with internal inductive drivers (IGN-1A coils). The ECU is just controlling a 5v signal to tell the coil to charge and discharge

 

[WFO Speedracer]

BTW there are a bunch of places that can repair Megasquirt controllers if that turns out to be the issue.