coil,tach,dizzy, I think i fried something

[TENDRIL]

L20b, matchbox dizzy, with Ei coil, factory tach

 

car turns over, wont start,

 

 

do not have spark from coil....

 

 

i think i messed up on wiring it back  together because when i turned the car to the on position after reconnecting everything there was a sparking/popping  sound coming from my tach and it was jumping around.

 

this is whats going on 

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the four wires i have been using (car would fire right up a week or so ago )

 

G/W - tach

B/W - tach (fatter)

B/L - ignition signal.  (i believe )

B/W - 12v with key on

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so the b/w wire on the left is coming from the tach. connected to the b/w wire on the left that is going to the +side of coil 

 

 

 

 

the white wire is going to the c on the matchbox

 

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because its this b/w wire (which is my 12v) that is connected to the b/g from the coil i dont know how this happened. 

 

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so this blue wire with the green splice in it. i had going to the coil and dizzy.

 

 

 

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i dont know WTF is going on i have been combing over dozens of threads and have wired every way i could find  for the tach and ei dizzy.

 

 

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so i started to test everything 

 

key on i have 12v to the POSITIVE  side of the coil, key off no power 

 

 

 

 

 

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as well as the NEGITIVE side and the inside  ??? is this right?

 

 

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check ignition  signal 

 

 

 

 

key "ON" .5 V

 

 

 

 

key "start" turning it over 12V

 

 

 

so that is functioning correctly, i believe 

 

 

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i read to test the negative side of the coil, with a test  light while turning car  over, i did that, it did not flash it stayed solid  

 

 

 

 

=======================

 

 

 

FML 

[Laecaon]

Ok first we need to know a few things. Like which tach do you have? 3 wire or 4 wire? Both were stock in 510s depending on year.

 

For now, to get your car started, or at least properly wired, we will by pass your tach.

 

Take the Black/Green wire completely out of the harness.

 

Take the Black/Blue wire (12V Start) and splice it in with the Black/White (12V IGN). Now connect the Black/White to the + side of coil.

 

Now also run Wire (supposed to be Black/White in color), from + side of Coil to B terminal on matchbox.

 

Run wire from Negative side of Coil to C terminal on matchbox.

 

[Laecaon]

Also your pictures dont follow. In one picture you have the Black/Green connected to the + side of coil, then you remove it...

[datzenmike]

Tach signal is from the coil negative.

[TENDRIL]

sorry guys if i was a bit jumbled, i was dead tired last night when i posted this.

 

 

 

ok i will try that again and report back,

 

 

so what i need help understanding, is how the coil, actually sparks.

 

the way i thought was:

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key on- 12v power to + side of coil

 

key start: signal to coil and B side of matchbox 

 

rotor in dizzy spins: elect. grounds - side of coil through C on matchbox

 

 

 

is this true?

[banzai510(hainz)]

Long as you have 12volt with key on the blk/wht wire

and 12volts on the blk blu on key START your fine and will get this running soon.

 

 

the blk grnn is supposed to be shorted the the blk/blu as its to complete the circuit to from the ballast to the coil.(will not be needed for you but just tape it off and keep wire stock)

 

I never ran a tach in 25years of Datsun ownership

[TENDRIL]

ok so i  wired blk/wht to blk/blu together to + side of coil and then to B on match box 

 

and a wire from - side of coil to C on match box 

 

 

im still not getting spark out of coil....

 

 

 

this is why i think i fried either the matchbox or coil

[banzai510(hainz)]

put the points back in.wire as stock then youll know if the box fryed.

 

you check you have 12volts on blk/wht wire if not ck the ignition fuse.

[TENDRIL]

I don't have points to put in .

 

I have 12v to blk and white with key on,

 

And 12v to blk and Blu with key start

 

And I've checked continuity to and from dizzy wires to ingnition no resistance so all connections in tact

 

All fuses brand new

 

Is the only way to check matchbox with points?

[Laecaon]

Mmk. How it works, + side of coil and B terminal of matchbox want 12V+ at both START and IGN key positions.

 

Mike, The tach does not necessarily run off the negative side. Stock wiring for the induction loop tachs actually show taking power from the Black/white wire, I.E. positive side.

 

 

With all wires still hooked up at coil and matchbox:

So if we know we have power at the coil and module (matchbox), we need to test if the module is working correctly. To do this, get a Test light. Not a Multimemter. Ground the test light, and then use the probe on the negative side of the coil. WIth IGN on you will probably see the test light shine. Have someone turn the key to start. With the motor cranking, you should see the test light blinking.

[TENDRIL]

Alright I did do that but not after I spliced blk wht and blk Blu, if it does not blink, match box is dead?

[TENDRIL]

I have had thi problem before and the car would not want to start unless tach was working,

 

could it have something to do with signal and ground from harness behind tach?

 

Like said before the tach started to make a sizzle and pop sound while jumping around when I think I hooked up every thing the first time wrong ,

 

It did this when I turned key to on, I shut it off .switched what I thought was backwards. it did it again. And now hasn't done it again...

[banzai510(hainz)]

Im guessing here I heard they were 2 nissan 510 type tachs the series type and the parralell type.

 

the ones from the store(after market I assume its parrallel and tach trigger off the - side.

This is why I say get rid of it ,discconnect it to make sure your ignition is working correctly.

 

Tendril. just place center coil wire to ground ck for spark and not worry about it your test light flashes. On points I know it works good but never really seen anybody use a test light to ck for flashing on a matchbox

 

 

we assume the car was running before now you just added the tach.which induced this proplem

[ggzilla]

Coil will read 12v on both sides because there is a wire inside. Only when the points close (connecting the neg side to ground) will one side read as 0 volts

[TENDRIL]

 

Tendril. just place center coil wire to ground ck for spark and not worry about it your test light flashes. On points I know it works good but never really seen anybody use a test light to ck for flashing on a matchbox

 

 

we assume the car was running before now you just added the tach.which induced this proplem

 

 

the tach and the EI dizzy has always been  in the goon since it came from troy ermish, and has worked for the last 4 years that i have had, and 3 before that when my buddy owned it.

 

the reason i took the wires off of the coil and dizzy in the first place was because i was trying to figure out why my horns were not working, and i was cleaning up my engine bay harness and re-wrapping it.

 

 

so as far as spark im not getting any with just the basic wiring for the EI dizzy  (tach un-attached)

 

blk/blu and blk/wht to + of coil than to B on matchbox and wire from - side of coil to C

 

checked with a test light no flash from - side of coil or C, just dimming from load

 

checked with multimeter for shits at the C and -side of coil 12v key on and barely drops to 10-11sh when turning motor over

 

held coil wire close to a ground turn over no spark not even a weak spark

 

 

is it safe to assume the matchbox is fried ?

[TENDRIL]

fixed!!

[TENDRIL]

it was the ignition module (matchbox) i fried it or something.

 

 

i replaced it with the GM HEI Ignition module set-up, and it fired right up.

 

 

thanks everone

[banzai510(hainz)]

great. show us how you fixed it with photo of the HEI using a matchbox dizzy

[TENDRIL]

Red +

 

black-

 

 

 

 

Red to Red

 

Black to green

 

at the dizzy