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62 Belair Ignition Coil Problem

 
MajorDez
I love my Chevy Chevette!
Posts: 1
Joined: 11/12
Posted: 11/24/12 04:52 PM

I am not getting a spark from the coil on my 62 Chevy Belair.  I have replaced the coil, points, and battery. The car sat for a little over a year since I inherited it.  Any ideas from the online guru's would be greatly appreciated!  

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waynep71222
My first time was in a Chevy
Posts: 218
Joined: 04/12
Posted: 11/24/12 06:54 PM

yes... a lot of things...

do you have a test light????  or a hand held digital volt meter???


and i will have to look at the wiring diagram for more info. but lets start at the coil..

take your test light/circuit tester...   hook the CLIP to the Positive side of the coil.. the terminal with the wires (2)  NOT connected to the distributer..    stick the probe of the test light into a something grounded.. so you can operate the ignition key...

turn the key from the LOCK position to the OFF position.. no light...

turn the key from the OFF position to the RUN position.. .  LIGHT.. medium brightness.

turn the key from the RUN position to the CRANKING position.. LIGHT full brightness.. release key

now that the key has been released from the cranking position.. and its resting in the RUN position.. the light should be back to the medium brightness..

this shows that the ignition and resistor bypass circuit are working properly...

so... LOCK and OFF.. no light..

RUN...   medium light..

cranking bright light..

Run   medium light..

off   no light..

more to come....  

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waynep71222
My first time was in a Chevy
Posts: 218
Joined: 04/12
Posted: 11/24/12 07:40 PM

so.. do you have power to the coil positive as described above..


if you do lets check the negative side..

pull the distributer cap....

you did not say which motor you have.. the straight six.. the small block or the 348/409 big block with the big scallops out of the bottom of the valve covers..

which set of points did you buy.. is the wire to the coil from the points attached with a screw?? or is it held in place by the spring against the plastic insulator block???  its really easy to  get that in the wrong position...  

did the points and condenser come as ONE unit...   did you clean the contact faces before you installed them.. manufacturers have taken to coating the entire points set including the contacts  to lengthen the time in storage before they start to look bad...

how did you adjust the points after you installed them????   these are usually adjusted with a dwell meter while cranking or while idling..  

have somebody crank the engine with the cap off.. can you see the points opening and fully closing..   they should be sparking slightly..  

if you get it running.. you can usually.. insert the allen wrench and turn the allen wrench to the left slowly until the engine dies...  then turn it to the right 1/2 turn.. exactly 1/2 a turn.. this should get you really close to 30 degrees of dwell... an old time mechanic showed me this trick.. i could take my dwell meter and hook it up after he was done.. and it would be somewhere between 29 and 31 degrees...


let me describe how the points type ignition system works...

when you turn the key on.. power comes from the ignition switch to the coil positive...  there is a resistance wire from the bulkhead connector to the coil positive..  there is an additional wire from the starter motor solenoid.. from the R terminal. this is the resistor bypass terminal...

during cranking the solenoid provides full battery voltage to the coil positive thru this wire..

this is why you get a medium bright light then a bright light while cranking then a medium when you release the key...  

on the negative side of the coil...

since electrons flow from Negative to positive...

when the points close.. there is an inrush of electrons from the closed points contacts to the primary wire to the coil negative to the primary winding in the coil... this creates a electromagnetic field..

as the engine starts to rotate with the starter motor.. the distributer shaft starts turning.. the points break and then make contact again and again...

when the points OPEN the electrons stop flowing..   the magnetic field in the primary windings of the coil collapses through the secondary windings.. this creates a HIGH voltage spark ..

so it takes a complete circuit for the system to make spark..

the ground path the electrons take from the engine block is thru the cylinder heads.. the intake manifold.. the distributer hold down clamp to the distributer housing.. to the lower breaker plate.. up the tiny braided ground strap to the upper breaker plate where the points and condenser are mounted..

if you position the crank shaft so the distributer is holding the points open. you can use an insulated screwdriver to touch the end of the points arm to the stationary contact... wiggling it will cause the coil to spark...  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/24/12 10:59 PM

MajorDez

1.Make sure the wire from the points side of the distr. goes to the Neg. side of the coil. If you have a dwell meter crank the engine, and try adjusting the points, (you didn't mention if it was a 6 or 8 Cylinder) it makes a difference for the dwell. Well for a V8 your dwell is 28* to 32*.
2.Does the dwell change? If not there is NO power to the points.
3.Check to see if there is a ballast resistor going to the distr.
4.If there is a ballast resistor check to see if it is open.
5.You can put a jumper wire across the ballast resistor,and see if the dwell changes. If it does thats your problem. The ballast resistor is open.
6.The ballast resistor I'm talking about maybe against the firewall or just hanging inline with a harness. It is usually white in color, but age may have turned it a yellow color or grease on it whatever. It is maybe an inch wide maybe five inches long and maybe an inch thick. 1"X1"X5".
7.Do you have 12 volts coming from the ignition switch when you go to start.
8.Check your fuse box

Bob  

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