91 MERCRUISER 5.7 IGNITION SENSOR

[BETZ954]

So i just got my new ignition sensor and it has the wires hard wired into it. also with a ground coming out. my original had the nut connectors, this new one has the red/white, red/green wires on opposite side as the original. should i just disregard the color codes an wire in same sides as my old or match the colors but that would seem to make it backwards from the way the nut connector sensor was. any thoughts?

 

[500dollar744ti]

I just got an OEM mercruiser ignition sensor and it just plugged right up like factory. It should come with a little kit to adapt it to the later style if you don't have that yet. What is the part number you got?

 

[BETZ954]

18-5116-1 replaces 87-861780Q4 fits all v8 thunderbolt ignition 1981-1997

it came with the wire adapters an shrink wrap an all that. its just the color coded wires are on opposite sides as original nut connector sensor.

 

[500dollar744ti]

Oh that's a aftermarket sierra part, it is the correct part though. You just might have to change some wiring around. I got the OEM quicksilver part and it was an exact match to the old one.

 

[500dollar744ti]

Because it's an aftermarket part, it could be manufactured differently and thus the wiring in different positions, I would absolutely match the color codes.

that's like picking up a battery for your car and finding the posts are on the opposite side, if you attempt to use that battery, you aren't going to just put the red and black cable to wherever they were before, you would have to switch them to make it work.

 

[BETZ954]

Because it's an aftermarket part, it could be manufactured differently and thus the wiring in different positions, I would absolutely match the color codes.

that's like picking up a battery for your car and finding the posts are on the opposite side, if you attempt to use that battery, you aren't going to just put the red and black cable to wherever they were before, you would have to switch them to make it work.

Ha, makes sense now. i guess being such a simple design i didn't consider it being wired differently inside but you can't tell being that its all sealed unlike the original nut connector one.

 

[BETZ954]

ok so i wired everything up started the engine up and its now missing. am i missing something here? installed ignition sensor, rotor, cap, connected ground to engine stud, red/white wire to existing, green/white to existing.

 

[500dollar744ti]

You probably have one of the ignition wires mixed up on the cap. If you had wired the sensor wrong, it would not start at all. One of the spark plug wires could have fallen off one of the plugs when you were moving them around on the cap as well.