Just wired up a SBC powered 29 Delivery at my shop using a painless kit. I fired up the car and let it run for awhile ,For about 5 mins, it then just shut off. Lost spark,The coil was burning hot. seems I killed the coil. I have power to the coil from the key.changed out the coil and still no spark.So now I think I also killed the Mallory unlite distributor. I am trying to find out the cause of this problem of the coil getting so hot. I thinking I am getting too much power to the coil. To me it seems The system needs a ballast resistor but I never seen a resistor on a GM setup before. Could it be a bad ground?? Looking for all the input I can get on this one.On thing i notice at the start of our fire up was The key was left in the on position for a min or so and I heard cracking noises coming from the coil!! The coil was warm at that time.I looked over everthing but could not see a problem so I fired it up. And 5 mins later all this happen. Hope I am clear enough on this. Any ideas??
if you are running any type hei dist you dont need a ballast they all run 12 volt if you are running points type dist you will need a ballast also if you are checking power during cranking and dont have an ignition lead running from the starter to the dist you will not see power during cranking. It is possible to start the engine without this lead if the motor is turning over fast enough after you let go of the key. Hope this helped RED
Two of my rods, both SBC powered, run Mallory magnetic pick up distributors. They both run ballast resistors. Did you forget to wire one into the circuit?
Double check all of your grounds. Fresh paint will raise hell with electronics. Replace defective ignition components and you should be good to go.
A lot of the origional wiring harnesses had a resistor wire running from the key to the coil. That might be why you don't remember a resistor, there wasn't one!
My Accel light triggered points replacement set up ( I believe made by Mallory ) says it has to have a ballast resister and also a "active power filter".
every mopar I've ever owned has had that style ballast resistor fail. use any other one or carry a spare.
WRONG! He already had non-defective components and was not "good to go" From the Mallory Unilite instructions: "Ballast resistor required, Active Power Filter is recommended.....you will need a ballast resistor installed in the system to prevent killing a good module" Summit and others sell the 700 resistor for 15-16 bucks. Plus you will need to replace your coil and module.
Did some research and It seem most here say the same thing. A ballast resistor is needed. I not use to all this aftermarket Shit. Use to using stock GM stuff. Seems on the Mallory site they say you have to run a ballast resistor with there HEI disturber. The module is gone too and it not a cheep part for a Mallory setup,seem it is half the cost of a whole new unit.I have another disturber to use and another coil. For safety I am still going to install a Ballast resistor. A few of you talked about grounds. I wish I had check them at the same time the coil went cause if they were warm I would have a bad grown. Going to keep a eye on that.
GM used a ballast wire. The wire drops the voltage. Usually light colored with a woven covering. You want 12 volts start- 9 volts run. You probably never did see a GM ballast resistor
Ground your engine with a good ground strap. I usually ground mine at the starter bolt to the frame. Sounds like your ground went through your ignition and fried it. If not grounded good the throttle cable will also fry. Good luck. King of the mercs
Sounds like you found your problem. I recall Mallory coils and distributors being sold with a Mallory ballast resistor. Like this http://www.summitracing.com/parts/MAA-29440/
Mallory distributors need a ballast resistor. As for a replacement module if you look on their web site the 6100M E-spark module is half the price and it will replace your fried module.
If you have the room, just run an original GM HEI out of a pre-computer car. No balllast resistor needed, run a regular wire (probably what the kit came with) and supply a full 12 volts to the cap/coil. Buy your HEI from your local wrecker (assuming you guys have them on "the rock" ) and when you buy the dist, purchase a second one that you can keep with you in the car/truck "just in case". Toss that Mallory in the "bin". In my opinion they just aren't neccesary on a street car. You want reliability? Go with original GM stuff. Just my opinion ... if you really feel you need a second opinion ... well then, feel free to ask me again . Sure, now people are gonna say "hey stupid, if they are so reliable, why do you feel the need to carry a spare" ... and the answer to that is, for the cost of a second used GM HEI (less than $50 each at my local wrecker) it just makes sense. I always carry a spare with me (in all my cars actually) and although I have never needed to replace one while on the road ... if I do have a distributor failure, I can fix it easily and that $50 spare HEI would have saved me a MUCH more expensive tow.
I guess I should add to my earlier post ... I am not saying Mallory ignitions are unreliable, what I am saying is ... you are going to need to repair your Mallory ($$$ apparently) and you are also going to have to add a ballast resistor (not $$$) ... I also agree that you need to make sure you have several ground wires ... engine to body, body to frame, frame to engine. My feeling is that although the Mallory may be a good ignition ... does it really make a difference on a street engine? This is what I mean ... take your vehicle down a dragstrip with an HEI, then take that same car down the same dragstrip with the Mallory ... there may be a difference that shows the Mallory to be superior BUT ... are you really going to "feel" that difference in a street car? Now, is the difference that was noted really worth the extra cost of a Mallory (or whatever aftermarket manufacturer) over a simple, cheap and reliable original issue GM HEI? How easy is it to find parts for a Mallory over finding parts for an HEI ... Ok, I'm done now.
I can't argue the "Ugly" bit ... they are certainly "cosmetically challenged" but I can live with that . Guess I should add, all my cars (past and present) do have hoods so they aren't easily seen. Ok ... NOW I'm done.
borntoloze I`m with you on the stock GM HEI. I have 6 or 7 kicking around my garage and used in all my own cars,even used them in my drag car,with some old school mods. The problem with this model A is the engine placement and firewall clearance do not give the room for the stock HEI setup. they may look "Ugly" but they never failed me. I believe if it is not broken don`t fix it. Being pretty won`t get you home!! As for the grounds I have one from the block to frame and body to engine and body to frame. The one that gives the most trouble is usually the engine to frame ground and I have a 3/4 inch braided strap for that one. I am concerned about this one cause both the block and frame have been painted and I want to grind all the paint off for a better ground but the customer might not like that.But if I see a problem It will be done regardless of what the customer might think.lol
Internal tooth star washers between the frame and lug, and lug and bolt. Or both sides of the lug. "If it ain't broke don't fix it" old saying, decades ago I started saying " If it ain't broke don't bring It here" now I hear it on TV. Mallory unilight came about just for guys who wanted electronic ignition in stock appearance (points) looking package. Hence the 12 start 9 run voltage required. The same as points. If you were to swap in the Mallory for the stock dizzy, No wiring problems, no changes, no modification. There are others now that just fit inside a stock dizzy. I'm almost positive thaat Mallory was the first. I ran one back in the late 80's and never had a problem. But lots of corners have been cut in 30 years.
Don`t think the tooth star washer will work. this car came to me over half completed and much of the frame is filled, hence the reason the customer don`t want me to grind the frame. I like the stock look of a stock point disturber but these after market ones look to bling for me. Billit bodys with shiny red caps. I`m a black cap person myself.lol
If the coustomer doesn't want a proper ground, then he needs to park it and use it for yard art. Without a good ground, the car just might end up in a cloud of smoke. Not everything is about looks. Sometime the customer must face reality. Oddly, Most automotive electrical problems, especially on hotrods and customs can be traced to faulty grounds.
Awe hell, if it was easy my little sister would be doing it. if the frame is tapped, run a tap thru That hole to clean all the paint or crap out of the threads. A dab of dielectric grease in the hole and another on the bolt should do it. Lots of surface area it those threads. If it's not tapped, tap it and see above. I'd be a bit Leary of using that frame for grounds, never can tell where that filler stuff will be. Bad grounds will make you pull your hair out.
I believe PerTronix came out before the Mallory Uni Lite's and also are the industry leader in Points replacement kits, having sold over 3.5 Million of them - more than all the other companies combined. They also make parts for some of the other companies. The current generation Ignitors are pretty much fool proof and they make them for just about any distributor made, including Mallory and Accel dual point. The biggest issues are voltage and as stated below, grounds. In most application they do not require ballast resistors as they can handle more voltage than the Uni Lite. Amen - One of the biggest causes of electrical failures To the original poster, leaving the key on with points or a Uni Lite, if the distributor is rotated so that a circuit is completed (luck of the draw) the coil will be receiving energy and not firing so it starts to build heat as it holds the electrical energy. If left on long enough, it will not only fry the points or module, but can actually blow up the coil - and that makes a real mess, believe me.
As far as grounds go, I'm old school in that I believe in having an actual copper cable from the battery terminal to the engine block even if you mount the battery in the rear. The starter is going to draw the most current and needs the best ground. Then ground the engine to the body and frame. With the battery in the rear, you need larger diameter cables to make up for the voltage drop the distance will cause. You might consider installing a fuse like electric forklifts use in the positive cable since the longer cable provides more opportunity for a short circuit.
Not to start this whole pissing contest on what's better, or who did it first The point I was making is the uni lite is set up to drop in and no modification of OEM wiring would be needed If your car had points originally. That is true. Simply reading the directions would lead to the same 9 volt requirements. I understand the OP inheritance of a half compiled vehicle. Right or wrong, inferior or superior, better or worse its designed to operate on 9 volts. The reason is stated earlier. It works a hell of a lot better than points. If you feed it 12 volts its not going to survive. If I was mistaken on the chronological order of release dates I do apologize, Mallory is local to me and I was aware of them first. Long before the internet.
This sounds familiar...I had a Mallory Unilite in my blown SBC 28 Ford Sedan Delivery, nothing but grief. You must use a ballast resistor and don't forget diaelectric grease under the module too. I used to carry a spare module with me (not cheap) and finally resorted back to a point style distributor because there wasn't enough room for an HEI. That was 25 years ago and at that time Mallory was the hot (pun intended) ignition to run. Good luck. ZAPPER
If you had a bad ground, you would not likely be replacing a coil and a module at this point. Although a good point was made about grounds with new paint.
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