No power to orange coil wire

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nomad007

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1980 xs650 special - sorted out charging issues went on 85 mile ride ran great - have voltmeter everything was good until end then felt like it wanted to stall- removed coil - posted on here member said it was probably mikes XS not original. while removing cow; wire came out of coil back. Bought MP08 on eBay - it metered correctly - new plugs ,caps and wires - no start. Seemed like only one side was getting spark and it was ok but not awesome blue. well red and white connector has power - orange wire does not. I think iI followed it back to same wire there was an orange connector in front of battery behind seat I unplugged sprayed with contact cleaner no power there. I did just replace rotor - messed with regulator and stator. Maybe I loosened something. Anyway I assume it is supposed to have power and is contributing to the no start. Before I figured this out I had the air boxes off and sprayed starter fluid in carbs to rule out a fuel issue, The carbs have seemed great tho - great idle and usually start, I did also replace the original vacuum petcock with manual as it was dripping on the on position when I had taken it off to work on battery issues. I did pug vacuum line. Any help would be appreciated. I have only had this bile a few months and did get to put several hundred miles on iy so far but now I guess I am getting to all the gremlins. thx Damon
 
nomad007 said:
1980 xs650 special - sorted out charging issues went on 85 mile ride ran great - have voltmeter everything was good until end then felt like it wanted to stall- removed coil - posted on here member said it was probably mikes XS not original. while removing cow; wire came out of coil back. Bought MP08 on eBay - it metered correctly - new plugs ,caps and wires - no start. Seemed like only one side was getting spark and it was ok but not awesome blue. well red and white connector has power - orange wire does not. I think iI followed it back to same wire there was an orange connector in front of battery behind seat I unplugged sprayed with contact cleaner no power there. I did just replace rotor - messed with regulator and stator. Maybe I loosened something. Anyway I assume it is supposed to have power and is contributing to the no start. Before I figured this out I had the air boxes off and sprayed starter fluid in carbs to rule out a fuel issue, The carbs have seemed great tho - great idle and usually start, I did also replace the original vacuum petcock with manual as it was dripping on the on position when I had taken it off to work on battery issues. I did pug vacuum line. Any help would be appreciated. I have only had this bile a few months and did get to put several hundred miles on iy so far but now I guess I am getting to all the gremlins. thx Damon
Click to expand...
well more research seems like the orange wire doesn't always get power or is a ground and get power while running? anyway all I know is now it won't start and I believe it has fuel and compression and ran well before this issue any ideas how to trouble shoot or verify black tci box is sound?
thx
 
Red or Red/White wire is power to the coil.
Orange coming out of the coil is the fire signal from the coil to the TCI box.
Easy way to isolate coil from iggy box:

Take the orange wire coming out of the coil and disconnect it.
Using a jumper if needed, rapidly tap the wire (coming out of the coil) to a ground... tap and remove, tap and remove...
Every time you remove (un-tap) the wire from ground, the coil should fire the plugs.... nice blue sparks.

If the plugs fire normally, it's a TCI problem.
If the plugs don't fire, it's coils, plugs and/or associated wiring.... or 12v power missing to the iggy system.
 
Did it ever run after the rotor was replaced?
If not does your replacement rotor have the magnet that signals the pickups for the TCI?
Late rotor with magnet.jpg
 
Jim said:
Red or Red/White wire is power to the coil.
Orange coming out of the coil is the fire signal from the coil to the TCI box.
Easy way to isolate coil from iggy box:

Take the orange wire coming out of the coil and disconnect it.
Using a jumper if needed, rapidly tap the wire (coming out of the coil) to a ground... tap and remove, tap and remove...
Every time you remove (un-tap) the wire from ground, the coil should fire the plugs.... nice blue sparks.

If the plugs fire normally, it's a TCI problem.
If the plugs don't fire, it's coils, plugs and/or associated wiring.... or 12v power missing to the iggy system.
Click to expand...
Jim said:
Red or Red/White wire is power to the coil.
Orange coming out of the coil is the fire signal from the coil to the TCI box.
Easy way to isolate coil from iggy box:

Take the orange wire coming out of the coil and disconnect it.
Using a jumper if needed, rapidly tap the wire (coming out of the coil) to a ground... tap and remove, tap and remove...
Every time you remove (un-tap) the wire from ground, the coil should fire the plugs.... nice blue sparks.

If the plugs fire normally, it's a TCI problem.
If the plugs don't fire, it's coils, plugs and/or associated wiring.... or 12v power missing to the iggy system.
Click to expand...
Hi Jim- I tried that with plugs in and it did not fire- I was getting spark before just seemed on one side and did not seemed the strongest but it was able to shock me - i will try new plug wires and caps unless you have some other ideas - just checked again with plugs out no spark with tapping - rechecked mp 08 - 3 ohms primary resistamce 14.11 plug wire to plug wire - i think i need new caps as i could not get reading thru caps - these are new but probably chinese - hopefully it is just something simple thanks for the reply - i also put new denso plugs in w22epu. thx
 
Dual output coils like the MP08 or the stock original usually either work or don't work. They fire both plugs at the same time so if only one side is sparking, that means there's something amiss with the other side's plug, plug cap, or plug wire.
 
nomad007 said:
Hi Jim- I tried that with plugs in and it did not fire
Click to expand...
Since the engine isn't turning during this test, there's no way the cylinders will actually fire.
Only way to know if the plugs are firing is to remove them and physically look to see if you get spark. Remember, both plugs need to be grounded when you test 'em.
 
Last edited:
Jim said:
Since the engine isn't turning during this test, there's no way the cylinders will actually fire.
Only way to know if the plugs are firing is to remove them and physically look to see if you get spark. remember, both plugs need to be grounded when you test 'em.
Click to expand...
ok.
 
nomad007 said:
How do they spark if the engine is not turning - sorry i don't understand
Click to expand...
When you turn the key on, it supplies power to the coil. When the orange wire is grounded (that normally takes place inside the igniter box).
That allows power to flow through the coil, charging it. When you remove the ground, the coil secondary discharges across the plug gaps, creating the spark.

For testing purposes, it has nothing to do with the engine. I've done this test multiple times with parts wired up on my bench.
 
Jim said:
When you turn the key on, it supplies power to the coil. When the orange wire is grounded (that normally takes place inside the igniter box).
That allows power to flow through the coil, charging it. When you remove the ground, the coil secondary discharges across the plug gaps, creating the spark.

For testing purposes, it has nothing to do with the engine. I've done this test multiple times with parts wired up on my bench.
Click to expand...
no spark like that- so i guess that is good box is not bad? - i took video but i dont know how to post. - both sides makes starting noise for a bout 2 to 3 seconds than orange spark --
 
Jim said:
When you turn the key on, it supplies power to the coil. When the orange wire is grounded (that normally takes place inside the igniter box).
That allows power to flow through the coil, charging it. When you remove the ground, the coil secondary discharges across the plug gaps, creating the spark.

For testing purposes, it has nothing to do with the engine. I've done this test multiple times with parts wired up on my bench.
Click to expand...
that is with one plug in and one grounded and starting - nothing happened with your both out tapping test
 
Jim said:
When you turn the key on, it supplies power to the coil. When the orange wire is grounded (that normally takes place inside the igniter box).
That allows power to flow through the coil, charging it. When you remove the ground, the coil secondary discharges across the plug gaps, creating the spark.

For testing purposes, it has nothing to do with the engine. I've done this test multiple times with parts wired up on my bench.
Click to expand...
 

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Don't think we're on the same page here. It's got nothing to do with starting the motor.

Key on, engine OFF.
Remove both plugs and ground them.
Tap test, id you get a spark on both plugs every time you tapped the orange wire.
 
Jim said:
Don't think we're on the same page here. It's got nothing to do with starting the motor.

Key on, engine OFF.
Remove both plugs and ground them.
Tap test, id you get a spark on both plugs every time you tapped the orange wire.
Click to expand...
yes i did exactly that - i got no spark -- photo was from other test
 

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