i just got a mollory unilite for my 68 f-250 390. The instructions say i must make sure my vehicle is equiped with an ignition ballast resistor or (loom resistance wire) between the ign. switch and coil, or i have to get a mallory ignition ballast resistor. How do i tell if i have one or the other? The dist has 3 wires coming out of it, a brown for ground red for + side of coil and green for - side of coil. The wire harness from the cab has the wire for coolant and one for oil pressure and one went to coil, do i hook up the one for the coil with the red from dist. to + on coil?and the green from dis. to neg coil,and thats it? I am not sure what other wires are supposed to be there cause most everything was gone when i got this beast.Any help would be appreciated I will be the first to admit i dont know much about ignition and bought a half cobbed together 68 f-250 and ripped it down to nothing and about $15k later im putting it back together! (looks like a centerfold beauty) but dont want to burn er' up.

 

250, Somebody will stop in with a better answer, but I think all of the electronic igns. use the same method. You are trying to keep 12V constant away from the system.

John

 

I would say you don't have either. I've used two of these distributor's (63 Galaxie, 352/85 Bronco, 351) and I had to wire in a ballast resistor both times. It's there to protect the module inside. One word of advice, buy and carry a spare module (#605) because they can, and will go out without warning at the most inopportune time (read: no speed shop within a gazzillion miles that carries said part ) Don't ask how I know that lol. Good luck.

Dan

 

Check the voltage going to the coil, it should be less than battery voltage if you have the ballast resistor or resistor wire. If I remember correctly it should be in the 7-9 volt range. The instructions should have a good diagram for where the wires go.

Black from the distributor to a good Ground -
Green from the distributor to the (-) Negative side of the coil -
Red from distributor should pickup a full 12V from the ignition switch -
Hot wire from the ignition switch (or from ballast resistor) goes to (+) side of coil -

A good safety is to run Mallory's Active Power Filter p/n MAL29351, it filters surges that will kill your $100 Unilite module and leave you dead on the road. See link below -

http://martelbrothers.com/product.php?productid=15585&cat=0&page=

 

Adding a $40 power filter to protect a $100 part that's known tho fail besides crippling the ignition coil with reduced current output because of reduced voltage by a ballast resistor sounds like a **** poor ignition system to me. Optical trigger yes but the rest of the system sucks. Your not the only one with failures, throwing good money at a bad product doesn't make sense, your wallet. Look into a Crane XR 3000, full voltage to the coil for higher secondary current to the plugs plus a optical trigger system that has very high reliability. JNO's
.....=o&o>.....

 

so which is better to use,a ballast resistor or the active power filter from mallory? i am assuming they both do the same thing but the conections on the ballast resistor have the ign wire and pos wire from dist both connected to the input and one wire comming out to the coil and the active power filter plugs into the dist. between the 2 plug ends in the harness

 

Got to have the ballast resistor or resistor wire in the harness to the coil. The Active Power Filter is an optional (I recommend) safety feature.

 

where can i get a ballast resistor any auto parts store? is it from mallory or what should i ask for

 

I would check with Mallory first to find the proper resistance ballast needed for their product they go with this ohms resistance number to your handy parts store or a wrecking yard with a meter. Make sure your not adding a ballast resistor in series with the trucks resistance wire. This will get you running but not protected unless you add a surge / filter. As you know this isn't a system I would add to my truck just to not have points but a ballast to reduce secondary ouput like a stock system.
.....=o&o>.....

 

The Mallory part number is 700. Here is the info on it from the Mallory website - Delivers 200-watt rating and uses threaded terminals for better wire retention. Available for most standard point type and electronic ignitions. Variable resistance values imporve cold weather starting and is rated at 0.75- 1.5 ohms. If you can find someone at a local parts store that has a clue, they may have something in stock.

 

If you cannot find one, here is a link -

http://martelbrothers.com/product.ph...27&cat=0&page=

 

thanks for all the help i will be getting both parts but i will check to see if i have a res. wire from factory before i get a ballast res. though, any clues where or how to check?

 

You'll need a voltmeter to check the voltage going to the coil, it should be less than battery voltage if you have the ballast resistor or resistor wire. If I remember correctly it should be in the 7-9 volt range.

 

thanks again i will check into it i wont be fireing the engine for a few days not quiet ready (waiting on a few more parts)

 

Remember now that voltage test is when there is a load is on the ignition wire source such as feeding the coil, if no load you'll read 12+ volts or what the battery voltage is at the battery terminals. Did you buy a Mallory electronic points replacement system or a complete mallory dizzy?

.....=o&o>.....