Thread: check coil

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need help. wifes 30 won't start. its a sbc. i checked and it getting gas. i put a timing light on it and get nothing. i used a meter and checked the + and - on coil with key on and get nothing. shouldn't i see voltage? i've never had a coil go out an don't know really how to check to see if its bad. since i'm not getting fire (timing light) i suspect the coil. help .

Depending on what kind of ignition you have hei or points. yes you should have voltage on both sides of the coil with the key on ... unless you have points and your points are closed. The easiest way to check it is with a test light turn the key on see if it lights up on both pos. and neg. if it does keep the light on the neg. side and have someone crank the engine it should pulse, if it does your coil is bad if it does not pulse your pick up/ or module / or points are bad.. hope this helps

simon

aitcharg, thanks i'll do that now. no points.

went and rechecked. getting 12v at both + and - on coil with meter. put a light on like you said and get no pulse from negative. so it looks like the coil is good?

i also checked the resistance between the + and - and get 1.9 ohms (according to any spec. i can find it should be between .75 and .81 ohms. the check between the poles and high tension is nothing, and spec says it should be between 10k and 11k ohms. any opinions? i'm off looking at the dist. and other wires. thanks again simon.

What's it look like under the distributor cap? Everything look okay there?

visually everything "looks" ok. i pulled cap and wires and looked for wear, evidence of arcing, i even pulled plug wires and did a continuity check to see if i had a busted wire. i replaced the starter and got voltage to it. have a cruise tomorrow so it looks like i'll be a few days until i can get back to her car. any suggestions are appreciated.

If you have no pulse on the negative side,then your found you problem.It,s time for a module,that is if the distributor is turning.

dist is turning. i will recheck the puls signal on - side. using light and meter i got 12v but no pulse. i'm going to reverify that i did it right. will be back on in a few days. will let you all know what i found. thanks again.

pull the rotor off look at the bottom side early hei rotors are famous for burning through if its burned through replace and check the ohms of all the plug wires the spark finds the easiest path to ground...ted

guys thanks for the help. it will not be until next thursday before i can get to this again. i have to go to my vacation place (where we are spending christmas) and hang moooorrrrrreeee lights. i didn't want you all to think i was ignoring you. i'll post results of what i find when i get back on it next week. again thanks for info.