I just repowered my 81 wellcraft with a 454 mag.

I have NO SPARK! I wired the ignition to this drawing

http://www.boatfix.com/merc/Servmanl/16/16F4R2.PDF

and have followed this troubleshooting procedure.

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

I have 12 V at the dist and coil, when I trigger the coil by grounding the white and green wire it still doesn't spark. I even tried another coil.

This says it is the Thunderbolt module is this possible? it was bought used from craigslist but was SUPPOSED to work.

The guy at the dealer says he NEVER sells ignition modules only the trigger units in the dist.

HELP!!!!

I would go with what the manual says. Before buying anything I would double check the wiring and make sure the kill switch (if it has one) is not pulled.

Good luck

Make sure the white/red and white/green wires are in the correct place on the dist. Also make sure your gray tach wire is not grounded.

x10

The module case/bracket must also be grounded.

I have thunder bolt IV ignition and mine quit sparking. Found out my tach was bad and shorting out the ignition. Replaced tach and works great

the flow sheet is straight foreward,if it is determined that the module is bad,replace it with a NEW one,remember,anything that is electrical can fail,i have had to replace modules before,despite what the parts guy said,they can go bad.

what power did the boat have before the repower?

maybe a problem with the throttle not being in neutrals when starting. Starter solenoids bad. You get any clicking or anything just no spark.

If the module case is not grounded, the flow chart will show that the module is bad, when in fact it is just not grounded.