Ignition wiring help - non-efi

[67EB_in_619]

So I am trying to help a buddy with some ignition wiring challenges... he swapped his ignition switch, coil, and starter solenoid because he was chasing a problem that turned out to be bad plugs.

Anyway, behavior is as follows:
Truck will crank and start but when key goes back to RUN, it dies.
Confirmed that ignition switch (OLD and NEW BOTH) dont have power at ign+ when key is in RUN position.

Let try to show this with a table of data:
@------------ACC Key Position---OFF Key Position---RUN Key Position
BAT Wire----12v------------------12v------------------12v
IGN Wire----12v------------------0.2v-----------------0.2v
ACC Wire----12v------------------12v------------------0v

I have been helping over the phone and expect to put eyes on the bronco later this week... but what I have "confirmed" is that the ignition switch behaves the same if it is the OLD or the NEW one.. while I get it is possible to get a bad new switch, having it bad in EXACTLY the same way seems like a stretch. I have confirmed that the starter solenoid has the purple wire on the S post, and the white wire on the I post (centech harness). The white wire goes through a ballast resistor to the + on the coil. He can "hot wire" it by jumping a wire from battery +12 to the I post to keep it running (how he plans to get it over here later this week).

I am at a loss as both switches seem to be behaving oddly unless there is a short or something downstream causing it to back feed the ign with the acc power, but it doesnt explain why there is no juice @ RUN.

I plan to hot wire things from the switch to see if that makes it behave differently, but aside from cutting into the harness, what suggestions to you smart fellers have?

Thanks in advance.

 

[Steve83]

Did the truck EVER run right on the Centech harness? Did these symptoms ONLY appear immediately after changing the coil & solenoid? Are you talking about the solenoid on the starter, or the starter relay on the fender? My first guess would be that he miswired the starter relay. Post pics.

 

[DirtDonk]

And double check that White wire too. There is a Blue wire that should go through the resistor, but the White wire should bypass the resistor.
Or worded differently, the Blue will attach to the resistor at it's "imput" side, and then run out to the coil positive. Depending on what type of ignition is in use of course.
Whereas the White wire will run from the "I" post of the starter relay, and attach to the "output" side of the ballast resistor, OR run to the positive side of the coil. Depending on how it's wired.

That section of the harness is left entirely up to the installer, so there might be some issue there. It's pre-wired along the passenger side fender, but at the 3-wire Weatherpack back there by the firewall, it's then up to the installer to run the wires to whatever ignition system is on the engine.

Seems like too, that your switches are either both bad, or as you said, there is some feedback somewhere. Obviously, at no point should an ignition switch ACC wire have power when the key is OFF. Nor should the IGN wire have power in ACC position, and none in RUN.
So something could very well be amiss between the harness plug under the dash, to the ignition switch itself. Is this the basic kit with a Centech supplied switch, or the one with the adapter to work with a stock switch?

Good luck.

Paul