CliffA
Well-Known Member
- Dec 29, 2009
- 4,712
- Boat Info
- 2001 Sea Ray 340DA
Name: 'Happy Place'
4.5kW West. Generator
Purchased Nov. 2014
Fresh Water Use
- Engines
- Twin Merc. 6.2L (MPI)
640 hp (Total)
Raw Water Cooled
V-Drive Transmissions
i am troubleshooting my Thunderbolt V ignition system due to a sudden loss of spark a couple weeks ago....can someone describe the current flow and operation of the hall effect ignition sensor located inside of the distributor?.....i have the new design sensor that is encased in resin and has 3 wires including white/green, white/red and black.....i have the color wires connected properly with the bullet connectors to their matching wiring harness wires and the black wire connected to ground.....
things i have checked so far....i have 12V on the white/red wire and 12V at the positive (and negative which is normal) coil terminals with the ignition key in the 'run' position but i get no spark at the coil...i have been working on this issue for the past couple weeks and out of frustration i started throwing parts at the problem and replaced the hall effect sensor twice, the coil twice, and the expensive ignition module once and still no spark....i have been through the TBV troubleshooting tree numerous times and always get stuck with no spark from coil....i have verified the throttle lanyard kill switch is good, the shift interrupt switch is good, the neutral switch is good, the 50 amp breaker is good, the ignition switch is good, the coil HT lead wire is good, the tach is not grounded out, and the rotor is turning when the engine is cranking over.....
this past w/e i even spent $50 talking to two different certified marine mechanics on the 'just answer' web site about the problem....we spent 2 - 3 hours working on the problem without getting anywhere.....their final suggestion was to replace the TBV system with a simplier Delco EST system for about the same cost as i paid for the TBV ignition module alone.....i prefer to keep the original TBV ignition system and since i have already spent so much monely on new parts i really don't want to spend another $350 for the Delco system....
i have a strong suspicion that the hall effect sensor and/or distributor are not grounded properly and not allowing the sensor to 'pulse' on the white/green wire as the distributor rotor is turning....as stated earlier i have the black wire from the new sensor connected to ground....i do not have a separate wire for a distributor ground....should there be a distributor ground wire?....should i add a ground wire to the distributor?...where would the wire connect to on the distributor?.....does this even make a difference?.....
for what it is worth the testing method in the Mercrusier manual for the hall effect sensor is inaccurate...the manual states to check the continuity between the white/green and white/red wires with an ohm meter and if the sensor is good you should see a reading of at least 100 ohms....i have checked three sensors (two of them brand new) and none of the sensors show any continuity at all between the two colored wires....i don't mean a '0' ohm reading...i mean absolutley no continuity at all.....either i don't know how to use an ohm meter (but i do) or i have 3 defective sensors (unlikely) or the mercruiser manual is wrong.....
normally i am pretty good at troubleshooting problems but this one has me (and two certified marine mechanics) stumped......
thanks...
cliff
things i have checked so far....i have 12V on the white/red wire and 12V at the positive (and negative which is normal) coil terminals with the ignition key in the 'run' position but i get no spark at the coil...i have been working on this issue for the past couple weeks and out of frustration i started throwing parts at the problem and replaced the hall effect sensor twice, the coil twice, and the expensive ignition module once and still no spark....i have been through the TBV troubleshooting tree numerous times and always get stuck with no spark from coil....i have verified the throttle lanyard kill switch is good, the shift interrupt switch is good, the neutral switch is good, the 50 amp breaker is good, the ignition switch is good, the coil HT lead wire is good, the tach is not grounded out, and the rotor is turning when the engine is cranking over.....
this past w/e i even spent $50 talking to two different certified marine mechanics on the 'just answer' web site about the problem....we spent 2 - 3 hours working on the problem without getting anywhere.....their final suggestion was to replace the TBV system with a simplier Delco EST system for about the same cost as i paid for the TBV ignition module alone.....i prefer to keep the original TBV ignition system and since i have already spent so much monely on new parts i really don't want to spend another $350 for the Delco system....
i have a strong suspicion that the hall effect sensor and/or distributor are not grounded properly and not allowing the sensor to 'pulse' on the white/green wire as the distributor rotor is turning....as stated earlier i have the black wire from the new sensor connected to ground....i do not have a separate wire for a distributor ground....should there be a distributor ground wire?....should i add a ground wire to the distributor?...where would the wire connect to on the distributor?.....does this even make a difference?.....
for what it is worth the testing method in the Mercrusier manual for the hall effect sensor is inaccurate...the manual states to check the continuity between the white/green and white/red wires with an ohm meter and if the sensor is good you should see a reading of at least 100 ohms....i have checked three sensors (two of them brand new) and none of the sensors show any continuity at all between the two colored wires....i don't mean a '0' ohm reading...i mean absolutley no continuity at all.....either i don't know how to use an ohm meter (but i do) or i have 3 defective sensors (unlikely) or the mercruiser manual is wrong.....
normally i am pretty good at troubleshooting problems but this one has me (and two certified marine mechanics) stumped......
thanks...
cliff
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