electronic ignition help...

Ohm both sides of the resistor, one will be 5 ohms, one will be

1.2 ohms or so. Use the 1.2 ohm side as described in the wiring diagrams that you found. This all assumes that your orange control box has 4 pin terminals instead of 5.

-Or- go back to the FLAPS and have them pull a ballast resistor for a 1979 Pick Up truck with a 360 engine. That should yield a single ballast resistor. (Echlin # ICR23)

Make absolutely certain that the control box is well grounded, run a braided ground wire between it and the engine block.

Mount the control box so it will receive some air flow to help keep things cool. (inner fender, firewall, radiator support)

Ayup, the instructions say to disregard one of the wires in the harness (the kit was never installed in a car, the guy just lost the ballast resistor) so I am ASSuming you are correct.

Thanks! That should get me going. Now to find some free time to run out and work on the beast again...

Just curious, what is the 5 ohm resistor for? ISTR a discussion about this a while back but don't recall the answer.

nate

Yeah, good luck getting that orange box to work reliably and last. They were good some years back (though no better than the stock box, flowery MP catalogue description notwithstanding); they got shittier a few years after introduction. Early failures are not uncommon.

When(!) the orange box in my '62 fails, I'm going to swap in an HEI module. It's a dead-simple swap, supports larger plug gaps and requires no ballast resistor -- two real improvements.

That'd be a dual resistor, which is not what is needed with the 4-pin Mopar modules. The dual resistor is used with the 5-pin modules.

DS

In article , Dodge-Him

IIRC, the 5 ohm resistor controls current to the base of the switching transistor, the 5 ohm resistor is now (on the 4 pin) mounted internally to the ECU making failure a box replacement instead of a ballast resistor replacement.

Carry a spare. Seems the best way to ward off evil spirits.

harness,

flowery MP

requires no

I have heard of that swap, and also am told that any number of aftermarket ignitions can be triggered by the distributor directly without a module... but I have the orange box now so I might as well give it a try. I thought however that the ballast resistor was more for the coil than for the module, i.e. if I use the stock Prestolite coil I still need the ballast; if I use an aftermarket coil with an internal resistor I don't need a ballast, yes? I was thinking it would be preferable to keep the ballast resistor esp. since I am using an Avanti (4-pole) starter so that I could install a bypass wire from the starter solenoid. (right now I am using the stock 6V wiring and a cheap aftermarket coil with internal resistance, but I'm not so much a purist that I won't do a little modification to the wiring harness.)

Just for curiosity's sake, can someone explain this to me or point me to an explanation?

thanks

nate

Measure both sides with an ohmmeter, and then connect to the LOWER resistance side. The other side was only used in EI systems through about 1975 (? or somewhere around there). Its a resistor that is internal on the newer electronic ignition boxes, which you can identify because they only have 4 pins in the 5-pin connector.

distributor

harness,

ballast

Chrysler, I

identify

AH now it kind of makes sense. So the higher resistance resistor in the dual ballast is some kind of power supply for the old control box which would be wired to the pin which is now unused on the newer boxes, yes?

thanks guys for all the help

nate

I don't know what it has for a shaft, I guess none or you will add one. Remember, the RB has a longer shaft than the B.

Ah, yes, I remember it well. :)

You can use either a 4 or 5 wire module.

Single ballast (.5 ohm) goes between the key and coil positive.

2nd resistor in blocks supplies pull-up current to something in the module. 4 pin boxes have that resistor inside the box.

This shouldn't make it run much better, unless something is wrong with the original distributor.

Close, .5 ohm and 5 ohm. The .5 ohm one is the one that gets hot and fails.

I wouldn't do that, some that vintage are 1 ohm. You need .5 ohm. One for a 61-72 Mopar (excluding dual-point Prestolite ignition) would be the choice. Or use the 4 pin resistor with the 5 ohm resistor connected or not. Do you have a FSM for a 73-78 Mopar?

One of the 4 wires is a ground, ground that while "making" the harness.

Using the stock Studebaker shaft and housing. The "head" of the dist. is the same as the old MoPars, just the housing and shaft are different. Specified B/RB because they rotate the same direction.

nate

Heh, sounds familiar... some things never change (that was the first advice I gave to my ex-GF when she bought her '69 Valiant...)

nate

oh yeah forgot to respond to this bit. There likely *is* something wrong with this distributor, as determined after a bit of back and forth on another newsgroup with the MoPar faithful... apparently the Studebaker-spec Autolite/Prestolite distributors used laminated steel advance weights without bushings, whereas the MoPar spec ones used weights with Oilite bushings pressed in... so the Studebaker ones have a real bad reputation for poor operation after only a few tens of thousands of miles whereas the MoPar guys apparently have no idea what we're bitching about as the MoPar ones work fine until the thing just falls apart from old age.

Now to digress a little bit... Studebaker also used Delco distributors for various models, both early and "window" flavors, and while those have a good reputation for durability at least one person who messes with performance parts for Studes (and the guy that put together this conversion that I bought, coincidentally (?) enough) swears that the Delco has a lot more variation in spark timing than a Prestolite in good condition. Not having an oscilloscope I don't have the ability to confirm/deny that but it costs little to buy "junk" MoPar stuff and mess with it :) (before you take offense I am not implying anything about MoPars, I used to drive a slant six Dart once upon a time and had a lot of respect for the car, I just mean old parts that *others* think are junk...)

nate

Hey!!! :p

The greatest thing in the world is to find a guy with 5 Mopar parts buried in a truckload of Chevy stuff at a swap meet. I know people that have picked up HP exhaust manifolds for $5 each, and 906 cylinder heads for $10 apiece that way :D

Both sides can and do fail, and you'll have a hard time finding a dual ballast with a .5 ohm side since all that appears to be available currently is 1.2/5 ohm.

Wanna take a guess what ohmic value resistor MoPar Performance has been shipping with their electronic ignition conversion kits for the last 20 or so years? Besides, dropping the ballast resistor value does nothing more than shorten the dwell time, coil saturation remains unchanged, coil failure can be expected from over current though.

Let's see... 4 wire ignition box

2 are for the pick-up coil 1 goes to the coil negative 1 goes to the J2 ignition on hot

Which one is the ground again?

Yeah, I've got a few mid 70s FSMs, I was working in a Chrysler- Plymouth dealership when these systems were as common as factory closings.

1978 (just FYI while I'm here)

Yes.

Don't use a coil with an internal resistor. Keep the ballast resistor idea. You could make a ballast bypass with one of those Bosch relays, or other. I'm not familiar with your starter. OH, does Avanti mean a ~1964 GM starter with solenoid? If yes, yes, you could use the ballast terminal for the bypass. (4-pole is likely a wrong description)

You can use a 4 pin ballast with a 5 pin module, the extra resistor won't be connected (through the module's missing pin). If you use a 4 pin ballast, you can use almost any module. If you use a 2 pin ballast you will not be able to use a 5 pin module.

Of course. :) I should have figured that.