Need a bit of help getting this thing firing

Congrats guys!!! Glad you stuck with it.

Yeeeha. Don't you luv the smell of sucess.:gringrin:

let us know if we can help more.

I believe that IH has a built in resistance wire to drop the voltage but don't quote me on that. I'll see if I can find a schematic. I'm sure mr mayben does.:winky:
 
Michael mayben posted a diagram of the ignition system for a 79 Scout II in post # 32 of this thread.

Btw --

if the wiring is original, IH usually printed circuit numbers (small) on the wires.

The wiring in my t/a is green - with numbers
 
Thanks Robert , I remembered seeing it but looked and didn't find it. :icon_eek:

wire by16-16 is fed by the resistance wire # 20 or that is fed by the ignition switch. Start at the ig sw and work forward.

Assuming the wiring is stock the resistance wire is usually covered by a woven heat resistant sleeve.

By 16-16 splits at the bhc. And continues to the coil.
 
It looks like one way or another I am going to have to get into the steering column and check out things there and see where that leads.
 
Don't tear into it yet. You can do the checks at the bhc first and chase the wire as far as you can towards the switch. Should have a plug that is easily exposed without taking the colonm apart. Check there next.
 
Good to hear that you got it running what was the final thing you did to get it to go?

As far as the wiring issue don't go taking the steering column apart the ignition switch is at the base of the column and can be accessed under the dash.

The switch is a standard GM unit, but there are 2 different versions one for the fixed and one for the tilt. They plug into the same connector however. Here is a generic GM ign sw diagram, the sii only uses the left half and the terminal in the lower rt "i1" is where the ign power originates.

http://www.chuckschevytruckpages.com/images/ignition.jpg


If you disconnect the plug you will see that it is in the shape of the left half with terminals sol (starter solenoid) bat1 & 2 ign 1 and acc.

Unfortunately I only have the early diagrams so I can't tell you which slot in the bhc it exits the cab through. Hopefully the cir # printing is still be readable at the engine side bhc. It will almost certainly be present at the ign sw connector and the cab side bhc.
 
So we have a cz17 wire going from the starter to the bhc that has continuity. The by16 is going from the coil to the bhc and it looks like either this vehicle didnt have a resistance wire or someone has removed it. By16 also has continuity from the bhc to the coil. So two questions:

1. How should it be rewired to accomodate the ballast resistor and also maintain 12v on start and 9v on run?

And

2. Does this mean there is definitely an issue with the ignition switch?
 
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Please...note that in my post where I provided you the correct wiring diagram for the vehicle originally described, I noted that diagram was not for a sii that May have been originally equipped with a breaker point distributor which requires either a "resistor wire" or a ballast resistor (but not both)! A resistor wire and a ballast resistor are simply two different type devices which accomplish the same end result!

You must decide which ignition system set-up you are going to use on a permanent basis. That will determine "which" wiring system needs to be provided.

If you are going to use a pertronix conversion in the breaker point distributor, then that needs to be accommodated. All you were trying to do when you started this thread was "make it run". The suggestion was to put a points distributor in and "make it run". That takes exactly a single "hot wire" from the battery to the coil positive terminal to "make it run".

If you are ready to progress to the pertronix conversion again...then simply install it and set the air gap. The red wire on the p-tron harness goes to the coil positive terminal, the black wire on the p-tron harness goes to the coil negative terminal.

But...when I suggested that you verify that you have the correct pertronix unit for the breaker point distributor you are trying to use, you never posted the results of that "check". So right now...we don't know what p-tron you have by part number! There are many possibilities!
 
It looks like a zck-1481 for the pertronix. I am thinking this May not even be the right one for this setup because it was purchased when the distributor cap was incorrect among other issues.

Regardless I am going to be perfectly content running points in here but neither will work until the ignition issue is sorted out.
 
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beastud said:
it looks like a zck-1481 for the pertronix. I am thinking this May not even be the right one for this setup because it was purchased when the distributor cap was incorrect among other issues.

Regardless I am going to be perfectly content running points in here but neither will work until the ignition issue is sorted out.
Click to expand...

A pertronix 1481 is correct for a Holley "curved points" distributor. And that is a "pertronix". A p/n 91481 is the number for the same distributor, but in the "pertronix II" version with adaptive dwell feature.

Attached is a .pdf of the "early Scout II cab and engine bay schematics, this is for vehicles equipped with a breaker point distributor and has a clear callout regarding both resistor wires used in the harness, the one for the coil feed, and the one for "field excitation" of the alternator. Do not confuse those two completely separate wire runs.
 

Attachments

  • Early SII Cab_Engine Bay Wiring.PDF
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It seems like she is running ok but the idle is a little high @ around 800 rpm. The strange thing is that the timing is around 40 degrees retarded. I don't know how it could run this well with the timing that far off, but it seems to get worse when it is adjusted. Not sure how it will perform under load because we are still running the hot wire setup.

Now to the real question. The ignition wire going to the coil (by16) cennects to an orange wire that goes to the ignition module on the steering column. This orange wire was competely fried. Could this be an indication of another problem, like a bad module? I still don't see any resistance wire as it was described before so I am assuming I will need the ballast resistor and run the wiring as shown by the last .pdf sent by michael (thanks!)

bottom line should this issue be investigated further or just replace the wire and go for the long awaited test drive?
 
Dont mean to hijack but need simular help I have a 79 sii stock with a elect. Ignition that went bad (prestolite).I put a Holley points dizzy in to get running. I got it running but timing is jumping (need rebuilt dizzy). When pulled the Holley out to put the presto back in with new control mod I notice the points contact was blueish like it was getting hot. Is this due to no ballest rester or wire? I put the presto back in set tdc to number 8 cyl. With the correct firing order im getting spark but not sure if it is strong enough to start. I have no problem with running the Holley with points if I cant get the presto to work. The control mod is new in the prestolite. Please help!!! Jason
 
The points are frying due to an "overcurrent" condition.

Primary current is controlled by dwell, coil primary resistance value, and voltage supplied to the coil positive terminal when the engine is running.

"blue" points after about thirty minutes of run time tells me from much experience in actually measuring primary current, that you will see in excess of 6.0 amps at idle. After about an hour of that, the insulated point contact will turn red hot and literally fold back on itself.

This is why either a resistor wire of 1.8ohm value, or a corresponding ballast resistor must be used in a breaker point setup on these engines. And...the ignition coil must be of the correct primary resistance value.

I've written about this extensively here in this sub-forum in several threads.
 
michael mayben said:
the points are frying due to an "overcurrent" condition.

Primary current is controlled by dwell, coil primary resistance value, and voltage supplied to the coil positive terminal when the engine is running.

"blue" points after about thirty minutes of run time tells me from much experience in actually measuring primary current, that you will see in excess of 6.0 amps at idle. After about an hour of that, the insulated point contact will turn red hot and literally fold back on itself.

This is why either a resistor wire of 1.8ohm value, or a corresponding ballast resistor must be used in a breaker point setup on these engines. And...the ignition coil must be of the correct primary resistance value.

I've written about this extensively here in this sub-forum in several threads.
Click to expand...
its alive!!! I dump the points. Put the prestolite back in and retimed it. Just needed a little more gas to start it but it fired. Checked the timing and the timing Mark is nice and steady. Runs grrrrreat. Now I can drive the heck out of it once the rain stops. Lol :icon_smile: (no top) thanks for all the help.
 
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