broken ground wire to coil. HELP

[91TBIguy]

i have a break in my ground wire(white) running to input(grey connector) on my coil. I have 10.5v on the hot (red) wire. I am thinking if i connect a ground to the white wire ill be able to fire it up? any ideas?
john,


1991 chevy s-10 4.3 TBI automatic 2wd...

[RahX]

the coil isnt permanently grounded, its a triggered ground thats how it fires. did you check it while cranking?

[91TBIguy]

well, no i did'nt test groud wile cranking. I did test it at acc. mode on ignition switch. Should i have tested it wile cranking?

I understand what a trigger is but how is it a triggered ground? its triggered intermintly so it fires coil? I just assumed that it was just a ground wire in the harness thats broken. Where does the white ground wire go to?

I guess i realy just need a engine harness drawing of a 91 4.3 tbi, but i have been unable to find it.
thanks for the help,
john

[unbe]

It gets its ground from the ignition module.

[RahX]

a coil fires like this: the power supply to the coil is 12v all the time. once the coil is energized the ignition module grounds it to fire it. it does this everytime the spark plug fires, well its the reason the sparkplug fires i should say. what kinda problem are you having?

[91TBIguy]

well The problem I am having is when the truck cranks theres no spark. SO i check the coil wire for sparks wile cranking and nothing. So i used my multi-meter to find out that i was getting no ground and 10v power to coil input at the acc. notch on my ignition switch. SO i assume that the coil wasnt getting ground, but form what i have just learned it gets ground from ignition module so maybe my ignition module is bad??? or the wires have been bumped. Ill check this... Keep the reply commin...
thanks all,
91TBIguy

[unbe]

I would assume you would want to check it in the run pos. instead of the acc. pos.

[91TBIguy]

check it in run? i checked it in acc. and i just re-tested it wile cranking and i still have no ground, it has to be the ignition module... going to put a new one in now.
john,

[unbe]

Originally Posted by 91TBIguy

check it in run? i checked it in acc. and i just re-tested it wile cranking and i still have no ground, it has to be the ignition module... going to put a new one in now.
john,

I should have said check it while cranking,it could also be a problem with whatever triggers your module or the wiring between them.

[91TBIguy]

Hey all,
Well, after picking up my $32.95 ignition module for my trusty local advanced auto supply. I installed my new module and gave my optima a little juice and she started right up... All is good in the the land of the 4.3, for now ... so anyway thanks to everybody who helped incuding rahX and unbe.
Peace,
91TBI guy