starting switch wiring question

[DiverRay]

Can you somehow bypass the kill switch? IF it's not right, the bike WILL NOT fire. I wonder if that could be a big part of the problem?? I'm at work, so I can't take the time to look up a wire schematic, but if someone can they can tell you what needs to be tied together. I think it's the red/white and red going to the right switch, but DO NOT go just on my memory!

[crazy steve]

Good call, and the wires are two red/whites going to the switch.

[PMKXS11]

Bypassed the kill switch and still the same result.

[PMKXS11]

Took the time and drew out how I have my bike wired. Does this make any sense?

[crazy steve]

That should work... I would check one thing though; make sure neither side of the solenoid coil is reading to anything besides each other. If there's an internal connection (shouldn't be), you may have a partial short when starting.

[DiverRay]

Steve,
It's a '79, and looking for the power from the starter to fire the coils BEFORE the main power takes over. He needs to tap the White/Red to the Red/White to have spark all the time, because of the missing ballast resistor. Check the wiring diagram for the SF.

[PMKXS11]

OK, changed the wiring on the bike to this:



This is how I interpreted what DiverRay said. I'm still getting a whole lot of nothing. Still getting fluctuation from the gray to ground and orange to ground during cranking. Still getting ~12v at the TCI during cranking.

Man this is frustrating

[crazy steve]

Your original wiring diagram is good. You don't need the white/red if the ballast resistor has been removed and the two red/whites are jumpered together. The TCI gets full voltage all the time, and if your drawing is correct, so does the coils.

[CaptonZap]

Here is a quick and dirty check on the switching transistors, which control the colis.
Unplug the TCI, and looking at the connectors, take a multi meter set on diode function, and place the red lead on the lower right spade of the 8 pin connector, and then on the two left spades, one at a time. (This is looking at the plug end of the TCI with the flat bottom down, screwed on lid up). You should get a reading of 500 +/-. Then reverse the leads, black on lower right, red on the left hand spades. You should get no reading.
If your's does not read like that, I would say the TCI is bad.
Don't throw it away, they can usually be repaired.
Hooking them up with reverse polarity will fry them, so make sure your polarity is correct.
CZ

[PMKXS11]

Your original wiring diagram is good. You don't need the white/red if the ballast resistor has been removed and the two red/whites are jumpered together. The TCI gets full voltage all the time, and if your drawing is correct, so does the coils.

Well when the rocker switch on the handle bar is closed, then the two red/white are connected and I get 12v at the coils and TCI. When it's open, it obviously cuts power to both (to kill the engine)

Here is a quick and dirty check on the switching transistors, which control the colis.
Unplug the TCI, and looking at the connectors, take a multi meter set on diode function, and place the red lead on the lower right spade of the 8 pin connector, and then on the two left spades, one at a time. (This is looking at the plug end of the TCI with the flat bottom down, screwed on lid up). You should get a reading of 500 +/-. Then reverse the leads, black on lower right, red on the left hand spades. You should get no reading.
If your's does not read like that, I would say the TCI is bad.
Don't throw it away, they can usually be repaired.
Hooking them up with reverse polarity will fry them, so make sure your polarity is correct.
CZ

I will give this a shot on both when I get home. I did hook up the original TCI I had reverse, but quadruple checked before I tried the new one.

[PMKXS11]

Original TCI: 542 and 538, OL and OL.
DiverRay's TCI: 542 and 541, OL and OL.
Within spec?

[CaptonZap]

Original TCI: 542 and 538, OL and OL.
DiverRay's TCI: 542 and 541, OL and OL.
Within spec?

Meter error.
CZ

[PMKXS11]

So my TCIs are ok, right? That means there's some other gremlin wreaking havoc

[DiverRay]

Do you have an ANALOG meter, or just a digital meter? With an analog meter you can disconnect the pickup coil plug at the TCI and verify you have a quick pulse of about .5V on the two lines as you crank the engine over. IF you have the spark plugs out, and lay them on the head, it will spin easier and faster. You should just see the meter deflection if you set it to 2 Volts. If you DON'T have any reading, that may be your problem.
Just trying to throw out more ideas, and trying to help with the trouble shooting.

[CaptonZap]

So my TCIs are ok, right? That means there's some other gremlin wreaking havoc

Not necessarily, all that did was check to see if the main switching transistors were shorted/open or not. There could be other components in the electronic stream that are shot.
Unfortunately, checking by substitution is the easiest way to find out if it is shot. Get one that you know works, and install it. If that cures the problem, you have your answer. If it doesn't, then you find another reason for the malfunction.
Was Diver Ray's one that he had tested and knew worked?
Try DiverRay's suggestion, and let us know. The four wires that carry the pulses are in the small four pin right side connecter, the top two being one circuit, and the bottom two being the other. There is a connector down on the left side that connects the pickup coils and the neutral switch to the harness. Make sure it is clean, as it gets a lot of crud buildup in it's location.

CZ