Mercury 1150 weak spark

I have a mercury 1150 that I got to run a little last summer after replacing the trigger inside the distributor, this season come around and im ready to put it on a boat and have some fun but when i go to link and sync it i have no spark again. I go through all the usually diagnosis and find that the trigger is fine but spark off the coil wire seems weak. It wont jump more than an 1/8 gap and its hard to get it to do that. My question is is it just a bad coil or is the signal from the switchbox weak? Is there a way to be sure its a full 12 volts getting to the coil?

There is more than 12v going to the coil you can use this chart to check the resistances.The coil wire might be defective or the switch box - check all grounds.
I had a weak spark and found this

I tested resistance and it all tested fine, and i checked grounds they also seem fine. I removed the coil to sheck for cracks and it looked fine untill i accidentally droped it on the ground and the outer plastic broke off of it, i believe there were some cracks i wasn't seeing. Is there any way to put a normal car coil on or is that just a bad idea? Also is there any way to know if the switchbox is ok?

Replace that coil, and don't drop the new one!

Jeff

Can only be 3 things....1) coil bad....2) switchbox failing …3) low DC voltage to switchbox

Yes there should be +12v to the red and white wires on the switchbox (4 terminal side).