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No power to coil

 
fandres16
I love my Chevy Chevette!
Posts: 3
Joined: 02/10
Posted: 02/28/10 06:36 AM

When I turn the switch to try to start the car, all instrument lights come on and will cranks the engine but will not start. No power getting to ignition coil. If I place a wire from the battery to the ignition entry point, when I turn the switch, it will start, if I turn the switch to the off position, it will remain running, if I disconnet the wire I place at the ignition, then it will stop, power is not getting from the switch to coil. What will the problem be.  

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canted
I have an SS396 tatoo
Posts: 499
Joined: 02/08
Posted: 02/28/10 11:55 AM

What vehicle are you working on?  
Jim
70 El Camino
461 solid, m20,
pics in readers rides
thanks for over 3000 views

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fandres16
I love my Chevy Chevette!
Posts: 3
Joined: 02/10
Posted: 02/28/10 12:47 PM

Is a 70 Chevelle, everything was working fine. two weeks ago, I started it took it out of the garage and shut it off. 10 minutes later when I to start it again, it didn't want to start.  

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65SSIMP
Everything in my driveway’s a Chevy
Posts: 549
Joined: 03/09
Posted: 02/28/10 03:46 PM

old wireing is full of gremlins. use a test light on your ignition block to find the keyed power to the coil. it could be in the igition itself or the wire leading to the coil. i'd start there,good luck!  

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waynep7122
I mow my lawn and find Chevys
Posts: 1130
Joined: 08/09
Posted: 02/28/10 07:47 PM

the ignition  power wire is pink off the switch...   it goes to the bulk head connector...

on the engine side.. it comes out as 2...  a pink wire to the idle stop solenoid...  and a resistance wire to the positive side of the coil...   it continues on from the positive side of the coil as a yellow wire to the 9 o clock position on the starter solenoid R terminal..



so.. do you get power at the idle stop solenoid on the carb????  

i would also like you to check the wiring that goes down to the starter... the yellow (smaller wire is the ignition bypass wire.)

how this works...   at the coil.. the power with the key on.. should be about 9.6 volts.. as the resistance wire cuts down the voltage.. this prevents the points from burning..    but during cranking.. the coil needs more voltage.. to make a hotter spark ... so the contact disc in the solenoid gets pulled across the contacts to spin the starter.. it also contacts the spring contact finger attached to the inside of the R terminal ..   this sends full battery voltage up the wire.. bypassing the resistance wire.. sending almost 12 .4 volts to the coil during cranking..

if this wire gets shorted to ground.. the resistance wire will burn off.. as some point in the harness..(under the hood only)



decades ago on a dark night .. at the donut shop at sepulveda and plumber in the valley.. a good friend had a V8 vega .. with a HOT SBC 383 in it..  he had just put a new starter on it..  and the R wire had contacted the battery post on the solenoid..  it would not shut off..  while he and i were standing there talking about how to shut the motor down.. it was idling at about 1800 rpms...  a third friend said i know.. i'll pull the coil wire..  before we could stop him.. he grabbed the coil wire.. and yanked..  except.. the coil was a mallory pro coil.. that the coil wire was attached tight to ...  it came off at the cap.. OH.. this little vega had an MSD 7A  ignition system...   there was what looked like michael jacksons glove on this guys hand.  it was blue voltage surrounding his hand.. up his wrist..   as the motor slowly spun to a stop..    since there were only a few who actually saw the electrical display..  and everybody wanted to..  no matter how much we prodded him..  he would not do it again..    that was a great night..   the cops chased some guy in a cad... from north hills to seal beach and back..    i heard later that chase went over 200 miles..  the cad had a full fuel tank...  it ran pd cars out of gas....

oh well..  

check the pink wire to the solenoid on the side of the carb... does it get power..

you may have to drop the starter and pull the wiring harness out of the tube to check it for shorts...

new resistance wires are available.. or you can replace it and upgrade to an HEI or other electronic ignition..

post what you find..  

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fandres16
I love my Chevy Chevette!
Posts: 3
Joined: 02/10
Posted: 02/28/10 09:34 PM

Thank you for the replies, FYI, when I turn the key, the starter cranks the engine, I check with the light and no power is getting from the switch to the resistance before it gets to the ignition. I was looking in an Ecklers Chevelle magazine, and they have a Steering Column Mounted ignition switch, but I don't want to buy it until I know if that's where the problem is originated. Thanks again.  


Frank  

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canted
I have an SS396 tatoo
Posts: 499
Joined: 02/08
Posted: 03/01/10 06:31 PM

As Wayne said, check the pink wire coming from the switch to the firewall connector. Fairly good bet if it is a forty year old switch.  
Jim
70 El Camino
461 solid, m20,
pics in readers rides
thanks for over 3000 views

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tfelectric
I love my Chevy Chevette!
Posts: 4
Joined: 06/10
Posted: 06/16/10 04:11 AM

ignition wire from switch to pos side of coil .you should have 12v at the coil when the key is in the on position . You can test it by putting a jumper wire from the pos (+) side battery to pos(+) on the coil . And the car should start but to turn it off , disconnect jumper . this means 12v constant feed is broken from ignition switch .  

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