a98lbweakling Posted June 15, 2012 Share Posted June 15, 2012 i've got a 85 brat with hitachi disty, and weber carb. the brat wasn't running before I changed out the carb, all taken apart when i bought it. The issue Im having is no spark. ive replaced the coil, disty, battery, cleaned the grounds and terminals, sparkplugs/wires/cap/rotor. There is voltage to the coil positive 12v, and the negative 5v. when i put on a test light to the negative coil to neg battery then crank it i get a faint pulse, but not too bright. fuel pump is working. the rotor is spinning. Theres one more thing, the voltage to the disty drops to 9v when it is turning over, the battery is brand new and fully charged. the coil shows 12.5k ohms and 2 ohms. Any wisdom would be greatly appreciated!!! Link to comment Share on other sites More sharing options...
naru Posted June 15, 2012 Share Posted June 15, 2012 (edited) Coil negative should be 12 Volts just like the positive. This suggests an ignition module problem to me. Take the wires off coil - and remeasure.Key on,engine stopped. Edited June 15, 2012 by naru Link to comment Share on other sites More sharing options...
a98lbweakling Posted June 15, 2012 Author Share Posted June 15, 2012 the blk/wht is at 12.6, and the small yellow is at 3.8. wires off the disty Link to comment Share on other sites More sharing options...
a98lbweakling Posted June 15, 2012 Author Share Posted June 15, 2012 Naru, thanks for mentioning that both the positive+ and neg- coil need 12v. i unplugged the module and got the correct voltage! and the flashing I saw in the dim light was nothing more than the starter flickering it. Im sure now that the problem has been with the old module, new/used module. Im gonna have to snag a brand new one to be sure:) Tossin another question to ya, I have 3 wires coming from the + and 3 from the - coil terminal. BLK/wht on positive and yellow on neg. Do you know what all these are for? i know only what 4 are for. the ones in question are, the positive blk that grounds out through a sort of cylinder about an inch long bolted to the coil braket and grounded on the engine? and a yellow with a white inline fuse. thanks for giving a hand in this mess! Link to comment Share on other sites More sharing options...
naru Posted June 16, 2012 Share Posted June 16, 2012 Black is a noise suppression capacitor(the cylinder). The inline fuse on a yellow does not sound stock,but,I could be wrong. The 3 yellows are tach,coil ground thru the module and ignition signal to the fuel pump control unit or ECU(shielded gray for ECU cars),IIRC. Link to comment Share on other sites More sharing options...
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