Scared myself, need some help

[Uriel]

After reading everything you've tried, I'm worried that you may have fried your EHC. There is a possibility of a fuse or a breaker being tripped but based on my 24 years of electrical background doubt its a fuse.. So this all started after installing a new battery, correct? You put a new battery in and it turned over twice and then boom nothing. So you buy a bigger battery and one that a lot of us don't run because experience has taught us those batteries (older versions) don't like the vibration from our bikes. But our bikes are rated for a 320 CCA battery which is 400 CA, you installed a 600CCA which is 750CA? So you almost doubled the amps running thru the wiring and circuits. Which a lot of us know that the wiring on these bikes are under sized from the factory. You could have burnt a wire in half with those kind of amps running thru them.

So, is anything electrical working on the bike at all? Turn the key switch on, don't do anything else, just look for a head lamp, brake lights, the sweep of your speedometer, try each turn signal, try turning on your 4 ways. check your tag light and if nothing you either have no power to the EHC or burnt the EHC up. Th check and see about power to the EHC you'll have to get the pin read out for the main harness and EHC track down the wire suppling power to it and see if you have power there. That is step number 1, once you determine if you do or don't have power to the EHC will determine step 2. There should be documentation on this site or you could call either Curtis or Knothead and they could send you the documents you need or post them.

Honestly hate you are going thru this. But one thing I learned with having a Bigdog, it will make you a better mechanic. Good Luck and once you get thru step 1 we will decide what step 2 is.

Sorry it took me a minute to respond directly, hadn't seen this post.
I got the bike with a defunct battery, nothing worked. Bought the big Li-ion, lights, horn, dash lights worked until I tried to start. Two cranks, dead. Reset the BMS on the new battery, same behavior, consistently.
Just got back from the battery folks with an AGM Duracell DURAGM-20L battery, fresh and new. As I was connecting it, positive side first, touched the negative cables to the battery terminal and it really did blow the EHC. With the key out, no known shorts.
I don't knew how to test to see what I damaged, suggestions? I assume I should not attempt to reconnect the battery again...

 

[Mickmorris]

Sorry it took me a minute to respond directly, hadn't seen this post.
I got the bike with a defunct battery, nothing worked. Bought the big Li-ion, lights, horn, dash lights worked until I tried to start. Two cranks, dead. Reset the BMS on the new battery, same behavior, consistently.
Just got back from the battery folks with an AGM Duracell DURAGM-20L battery, fresh and new. As I was connecting it, positive side first, touched the negative cables to the battery terminal and it really did blow the EHC. With the key out, no known shorts.
I don't knew how to test to see what I damaged, suggestions? I assume I should not attempt to reconnect the battery again...

Oh yeah that’s tits up. And it does look like the stock EHC. Get you a Axle replacement & you will be up & running in no time. Takes about 30 minutes to connect. Never use a lithium battery on these machines. They will bite you eventually

 

[Mastiff Rider64]

Sorry it took me a minute to respond directly, hadn't seen this post.
I got the bike with a defunct battery, nothing worked. Bought the big Li-ion, lights, horn, dash lights worked until I tried to start. Two cranks, dead. Reset the BMS on the new battery, same behavior, consistently.
Just got back from the battery folks with an AGM Duracell DURAGM-20L battery, fresh and new. As I was connecting it, positive side first, touched the negative cables to the battery terminal and it really did blow the EHC. With the key out, no known shorts.
I don't knew how to test to see what I damaged, suggestions? I assume I should not attempt to reconnect the battery again...

Yeah I think with the Big Li-ion battery when you went to crank it you shorted the EHC, then when you touched the neg to the positive you popped something else. I agree with Mickmorris that does look like the original EHC. The only way I know to test one is to send it to Curtis (aka Wildsteedworx) let him test it but 90 percent sure its gone. You can get a AXLE replacement from Curtis or one of the other suppliers of Bigdog Parts I believe or try to find a good used one. I have a spare for each one of my bikes, one carb, one FI but they are stock Bigdog replacements I bought from ppl I knew were straight up ppl. But the quickest way to get back on the road is to buy another EHC install it and then connect your battery. If you didn't burn up your starter solenoid with the big battery you should be fine.

Keep us updated.