Ignition sensor tests bad after installing new engine

[thestigmach1]

Recently traded for a 1984 sea sprite 25ft. Has 350mercruiser in it. 4th time out engine developed a horrible knock. Yanked it out and installed a truck 350 to get me by while I rebuild the other motor the way I want it. Guy I had helping me put all kinds of things wired wrong and backwards on the alternator and starter. Trying to get it running I have no spark. Using the forum I found helpful posts to test the situation and found that the ignition sensor seems to test bad. Before i go to order a new one is there anything beyond the diagram i should check to make sure or is that pretty sure fire?

 

[achris]

If you disconnected the tacho and shift interrupt wires before the test, then the sensor is it.

Chris.....

 

[thestigmach1]

The white and green wires on the distributor right?

 

[achris]

The white and green wires on the distributor right?

Tacho wire is grey, and runs from the coil negative, the shift interrupt wire is white/green and runs from the sensor.

Chris.......

 

[thestigmach1]

Tacho wire is grey, and runs from the coil negative, the shift interrupt wire is white/green and runs from the sensor.

Chris.......

Ordered a new one this morning before I saw your post. Found one on amazon for 40 will be here Tuesday. When I tested it I left the grey wire attached to the coil. If I strike the white green wire on ground the plug sparked. If I connect the wire and crank it does nothing. Hopefully it is in fact the sensor, the one in there is kinda nasty looking anyway so probably should be replaced.

 

[achris]

Hopefully the new sensor is the revised one (3 wires) and not old stock of the original (2 screw terminals).... It should come with a couple of adaptor wires to convert your wiring harness to take the new sensor... The 3rd wire is black and gets attached to any good ground on the engine block.

Chris....

 

[thestigmach1]

Hopefully the new sensor is the revised one (3 wires) and not old stock of the original (2 screw terminals).... It should come with a couple of adaptor wires to convert your wiring harness to take the new sensor... The 3rd wire is black and gets attached to any good ground on the engine block.

Chris....

It is the new style with the wires. Since I got spark when striking the white green wire no chance of bad ignition module right?

 

[achris]

It is the new style with the wires. Since I got spark when striking the white green wire no chance of bad ignition module right?

That would indicate the module is working as designed.