Wiring Help

[AggiesaurusRex]

I'm still in need of some electrical help from the more experienced XS11 folks.
I'm on the final stages of a rebuild and have done everything I can do to fix and track down the problems myself. But I have no voltage to coils and no idea why.
I have an 80 XS11 standard, harness was destroyed so it was remade completely.

Somethings I have figured out:
I have 12.5 Volts INTO the TCI.
Kills witch works, and has 12.5 V through it and is not the problem.
No tip sensor, no ballist, both were removed by previous owner.
Battery is brand new, has 13V
I have accel coils, mounted under the tank by L brackets, it's a good ground.
Sometimes if I hold my mouth just right I randomly have voltage to coils (12.5V) but it's gone the next time I try.
Typical read for the coils is 0.3V

If you have any idea what this could be please give a shout.

[3Phase]

Aggi, does the the starter motor crank when you push the button?

Measure the voltage at the Red/White wire on the Start Solenoid. The entire ignition circuit runs a big circle (circuit):

Red/White wire:
Fuse Box
Stop/Run switch
Wye junction for the Ballast Resistor and Ignition Coils
TCI
Starter Solenoid

Blue/White wire:
From the Start Solenoid back up to ground with the Start button

Other places to look:
Measure the voltage at the TCI connector Orange and Gray wires.

At the former Ballast Resistor connection

The coil Primary and Secondary terminals.

[motoman]

Added to what 3Phase recommended, since the Stop/Run switch completes the voltage circuit, I suspect dirty contacts in the Stop/Run switch to be the issue. That would be an easy and good place to start. I say this cause that was location 3Phase found a serious voltage drop on my Venturer when he was here at my place for several days a few yrs. back. I'm sure that switch, with decades of exposure to mother nature elements has corroded cruddy cotacts irregardless. Unplug and remove from bars. Take apart CAREFULLY so teeny internal spring doesn't boing somewhere and cannot be found. Now, immerse ALL pieces including switch in a shot glass full of Evapo-Rust overnite. Remove, wash clean with water and blow-dry pieces. Re-assemble, install and plug back in. That at least eliminates that as an issue, as that switch contacts IS a known common voltage failing location

[CaptonZap]

One other thing to remember is that the TCI shuts off the current to the coils after some seconds, (depending on the condition of some internal components)
if it doesn't get a signal from the pickup coils.
Clip one of your meter leads to the red/white wire leading to the coils, the other to ground, and then turn on the key. You should get 12V+ for 10 seconds or so.
If not, trace and check for continuity of the wire from the coil to the third terminal from the left on the bottom row of the 8 terminal socket on the TCI. (When looking at the TCI sockets)
If that wire is good, check voltage from that terminal to ground. If no voltage, odds are the TCI is kaput.
CZ

[TopCatGr58]

Late to the party,

You said no ballast resistor, harness redone. With an OEM harness with aftermarket 3.0 ohm coils folks have to BYPASS the resistor by putting a jumper across the ballast resistor connector so that the power continues along the circuit to the coils. Not sure how you rebuilt the harness, but if you kept the ballast resistor circuit, but just unplugged the BR, then that could be where your power has stopped? JAT!

There is a MOD that some folks have done where they wire the coils with a Keyed on/off 12V tap directly from the harness to the coils, or even directly from the battery, but suggest from the Keyed harness connector at least.

T.C.