hi all. i'm a long time lurker, first time poster, but i'm at my wits end with this truck. i've got a weak spark condition. it's getting fuel. i've replaced, coil, plugs, wires, dist cap/button, distributor itself, with no luck. i was troubleshooting with haynes manual and think it may be the ballast resistor. i measured 11.8 von batt in run position, so i proceeded to check primary resistance from batt term to red wire and got 5.5 ohms. it should be .8-1.6. manual said to replace ballast resistor wire. so now i have completely ripped apart my dash trying to find this damn thing, but don't know what to look for. where is the other end of the ballast resistor? i'm just stopping before i tear anything up, haha. what color should the wire be? and where is it found on both ends? thanks in advance for any help!

 

There is no ballast resistor on a Ford TFI style ignition system. Sounds like you were following the instructions for a Duraspark ignition system.

 

oops. i'm a dummy! told you i was a newbie. well what ideas do you have for my lack of spark? it seems to me i have replaced every component. the grounds seem fine to me, unless i've missed one. which grounds would account for these symptoms?

 

Ignition Control Module (aka TFI), has it been replaced or tested?

For reference: Fuel Injection Technical Library » Thick Film Ignition (TFI)

My buddy Joel5.0 has a great write-up here for a no spark condition: SBFTech.com TFI Module/Hall Sensor Testing Procedure

 

thanks a lot. i'll test all these. i have already replaced tfi.