Jump to content

Testing a pertronix set up


Recommended Posts

So I have had some issues with getting my truck running after swapping points for a pertronix. It came off another truck and was fine.. I have static timed it..many times.still won't run. So thinking it may be pertronix. Any help on how to test would be helpful. Thanks 

Link to comment
  • Replies 37
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

I don't think you can test a Pertronix, or at least, I don't know how.


I do know that they will burn out if you use the wrong coil. They require a set range of OHMs. Pertronix figured out a long time ago that many people were doing this wrong and started selling coils too.


Did you install the Pertronix coil too?

Link to comment

Pull a plug wire, put an old plug in the end, hold against the head and turn the engine with the starter. Got spark?


Set TDC compression stroke on number one cylinder. Check that both number one cam lobes are pointing upwards at 10 and 2 o'clock to be sure you are on compression stroke. Now look at rotor position. It should be under or near the number one plug wire on the cap.


With spark and approximate timing it should at least try to start.



Coil should be for a points distributor with a 1.5 ohm resistance and a 1.5 ohm ballast resistor. Or you can run a 3 ohm coil without the ballast.

Link to comment

Good to know. The EI in Datsuns has a safety circuit that shuts it off if no pulses detected from not running. It also has a current limiter so won't blow up if you use some wizz bang low impedance after market coil.

Link to comment

just pull the center wire from the dist cap and place near ground. START. if it sparks and starts snapping the Pertronix is good. weither the motor is timed up or not.


I never had a Pertronix go bad myself. I had the Magnet ring tape peel off the the magnets get stuck to the dist.  I I buy a extra magnet ring. Nail Polish the edge of the tap so it dont peel.


Pertronix will go bad if not ballast resisitor in system and left ON.


Mallory Unilites would go BAD also if no Ballast resisitor.


Shit I was in San Antonio recently!!1 I could have installed it then.  Horribly Place too HOT.  I was right on the River Walk Crockett street(hotel)



Edited by banzai510(hainz)
Link to comment

Ok so I checked my Pertronix and I got spark. And I also got spark at spark plug #1. So it has to be timing? Yes/no? I hate this crap. I feel I had it timed right. But still nothing. I sure don't know what the heck I am doing. Sorry I am not much of a mechanic. Steve (Redeye) and Hainz have always helped me out with the big stuff. I am not sure what up I guess back to the drawing board. 


  • Like 1
Link to comment

I think a 77 was Point truck vehicle like your chop top that installed the Lat Pertronix.

Your photo DONT have a ballast just coil so was this truck running with points?????????????????


What does the coil say?


If you can find a Old School VW or British car place I bet they can get this going fast

Edited by banzai510(hainz)
Link to comment

'78 and '79 L20Bs were EI except California emission trucks which had some kind of EI from '76.


The blue coil does not look stock so find out what the primary resistance is because without a ballast it should be around 3 ohms. Otherwise 1.5 ohm coil and 1.5 ohm ballast.

Link to comment
21 hours ago, 1lo620 said:

Well the picture is the coil set up I have, it is a stock 77 620. With factory tach. No ballist resistor...does that mean so what 


19 hours ago, David Krouse said:

Hell at this point should just go back to points..

What is happening here lol.
Do you need me to fix your account again? 

  • Haha 1
Link to comment

It may seem simple for you all but I am not a mechanic. I have explained this to Steve.and Hainz. I don't have a timing light I am struggling to statuc time it. As steve has shown me...I enjoy the custom aspect and the style of the 620s. But unfortunately I really have nit learned to work on them. I have had friends and shops do the work over the years.  So if I can't get this figured out. More than likely it will need to go to a shop. You all are mechanics and the 5he how toos and enjoy it...I do not

That being said,, the coil had no ballist resistor .. if I need to put one on how is that done. And I don't know how to adjust the pertronix distributor plate 

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.