Hi, I have a 94 4.3lx with the thunderbolt ignition. How many volts are supposed to be at the coil? I think it is supposed to be 12v correct? I know older engines with points need to be lower with about 9v but I dont think that applies to electronic ignition. Am I correct? Thanks.

Yes 12 volts.

I thought that some of the TB's were under 12 volts? My Formula it is lower I beleive. I do know that there is a wire that runs from the starter to the coil for when you are cranking to "boost" the voltage.

I'm going off memory, so I could be mistaken, but pretty sure the purple/key on wire at the coil should have 12 volts.

i was thinking at least 45,000, assuming you have a competition coil

All modern ignition systems (ones without points) should have 12 volts at the coil + terminal Point type ignitions systems will have 12 volts at the + terminal of the coil ONLY when cranking and maybe 9 volts at the + terminal when the engine is running.

12.6 + with just the ignirion on and 13.8~ 14.2 running..

http://www.boatfix.com/merc/Bullet/83/83_24.pdf

Thanks everyone for confirming the 12 volts!

Bump:

Having issues with my boat not restarting after running great. It turns over but wont fire. Noticed 11.3V at the + side of the ignition coil, is this why it wont fire?