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Mercruiser 5.7L Thunderbolt Ignition/Coil

Delta8500

New member
1983 Larson Delta 8500, 260 Mercruiser engine with Thunderbolt IV ignition
Engine wouldn't start. I checked voltage at the coil and I didn't have 12vdc with the key on. I had 12v from the + terminal on the coil to ground (engine manifold) but not between + and - on the coil. I traced the negative and saw it went through a micro switch connected to the shift linkage. The switch was opened so I jumped it out. I now had approx 9v at the coil but the engine still wouldn't start. I put a jumper from the battery + terminal to the Coil + terminal and now had 12v on the coil. After attempting to start again I noticed oil coming out of the coil and it was very hot.
Does this point to a bad coil or did I damage it but applying 12vdc directly to the coil.
 
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