The control box is looking for a DC signal, somewhere between 0.1 and 5
microamps, depending on the brand of control. Most ignitors have
separate leads and electrodes for the ignitor and sensor. The wire
with the thick insulation is the spark , the other wire is the flame
sensor. Some controls use a single wire/electrode. If the electrode
does not have a good ground back to the control box, it will not work
well. You may need a competent tech to fix this, as it is, you are
playing with fire, no pun intended. With gas, screwing up could be
dangerous. You can also go through a lot of parts before you get it
fixed. You can also damage new parts if you wire it wrong. If it is
more than a bad ground, I suggest you call someone. It's not like the
old days when a homeowner could replace his own thermocouple. This
high tech stuff requires training to fix right.

Good luck

Stretch