what would cause my coil to burn up?

[meathead333]

since ive installed my stereo, this is the second coil ive burned up. when to burns out, it literally burns up. this last one kind of, slightly bubbled out and was to hot to touch. i cant say for sure, but i think it is from running my stereo when my bronco is not actually running. i dont have an "accessories" selection on my ignition, so when i go to use the radio when the truck is off, i just turn it to the right one notch anf let the music play, sometimes for an hour or so whil ei work on what ever. you think that would cause it? my stereo is hooked up to the fuse box, not directly to the battery. someone also suggested that my truck may not be grounded correctly, is that a possibilty too? help!?!?! ?:?

 

[ransil]

Does your truck have points?

When in the acc position the vehicle does not supply power to the ignition. Since you have no Acc position you have power on the coil if you have points and they are closed then the circuit is completed and current will flow, coil is not rated for constant duty and will burn up. Not sure if this is possible with a dura spark ign.

 

[meathead333]

Does your truck have points?

When in the acc position the vehicle does not supply power to the ignition. Since you have no Acc position you have power on the coil if you have points and they are closed then the circuit is completed and current will flow, coil is not rated for constant duty and will burn up. Not sure if this is possible with a dura spark ign.

no, i replaced the points with an ignitor(sp?) setup. ok, so as long as i dont run my stereo while the engine is off, i shouldnt burn out the coil, correct? i am just hoping i didnt mess up the stereo wiring, i really dont want to rewire it just to trouble shoot the problem unless i know that is the problem.

 

[broncnaz]

Shouldnt be a problem to rewire the stereo you should have some point that runs in Assy position. But what ever is more important to you stereo or being able to drive it. What type of coils are you burning up? some coils like stock types cant run on full voltage all the time the stock system has a resister 2 ohms I think the only time it gets full volts is during startup. If you dont have this resistor and your running stock coils that will burn them up.

 

[adunham]

I had a 66 GT-350 clone (no stereo) that did the exact same thing. A new coil would burst every two weeks or so and spill its guts all over the engine bay (looked like a melted candle). I called up one of the local Mustang shops in Denver (Monty's I think) and they said it sounded like a bad voltage regulator. So I replaced it along with new wire for all of the connections and the problem did not come back.

-aaron

 

[76Broncofromhell]

I don't think a Duraspark will keep a circuit closed but those little ignitors I'm not sure about. The whole reason factories put in the accessory tab on the ignition was to keep the coil from exploding all over the place if you needed stuff on with the engine off.

 

[Bronchole]

I use to have the same problem with a Crane ignition that replaced the points just like the ignitor. You have potentially 2 problems.

Somehow you have wired the stero up so that it is backfeeding the ignition system. You do need to fix that because you don't want to have someone turn your stero on for you or accidently leave it on but with the volume all the way down and have it blow you coil. It is likely that the lead from you stero that is supposed to go to a switched power source needs to be moved. If you want to be able to run your stero without the switch on, hook this lead up to where the memory (full time positive) lead is hooked up.

The other problem may be that when the Ignitor system was installed the power for it was ran so that it bypassed the resistor wire that was running the points. On my Crane sysytem this was my problem. The resistor wire limits that ammount of current that the ignition controller can drop across the coil. Still enough to correctly do the job, probably will heat it up pretty good if left on, but not running, but not enough to blow it up. I fixed min by using a $20 more expensive version that had built in current limiting and never had the problem again.

 

[Broncobowsher]

Somewhere I have a book on the different eletronic ignitions. The early ones would default to keeping the coil hot with the engine off. Later they discovered technicians would leave the key in run while working on the cars. This was killing coils. So a later version put in a logic that kept the coil off unless it saw a signal.

Another ignition I remember was back when Super Shops was still around. They had a Mallary display that had paperclips sitting on one of the big square coils. As you spun the distributor (Unilite?) you could watch the paperclips dance around. Set it right and the paperclips would stay standing. So even some of the aftermarket stuff would keep the coil on.

So just do the right thing and move the radio to the accessory post. Keep the coil off while listening to the tunes and let us know when you are ready for a dual battery set up with isolater so you can start the truck the next morning after listening to the tunes all night.

 

[meathead333]

ill have to mess around with the stereo wiring. i have a centech harness, i forget what point i put the power wire at. i am going to test the couil the next few days by not using the stereo when the engine is off and see how hot the coil gets just from normal use. how hot should it get? i do know this...the coils ive been using say something about needing a resistor. i dont know if i have one or not. where would it be and what does it look like? i read in some other posts that that may be the reason also. anyone in the tacoma area wanna come take a look at it ?:?

 

[cynrays]

Why don't you just run the stero to the battery along with a fused wire for the hot wire? That is the way I ran my CB and Radio...

 

[SaddleUp]

Another area of concern when the ignition is in the run position without it running is the alternator. We were working on one a couple of weeks ago that was too hot to touch after the ignition sat on for an hour or so.

 

[meathead333]

ok, well i put in my new coil. i went for about a 25-30 drive. when i got back i opened the hood and and the coil was pretty hot. how hot should it be? mine is mounted on the engine block, will the heat transfer from the block effect the coil? also i mentioned earlier that the coil ive been using says i need an external resistor. i dont know if i have one or not. can someone explain that to me. if i dont have one, should i be using a different coil? or do i need a resistor, if so, which one. thanks.

 

[broncnaz]

If your instructions for your coil requires a balllast resistor then use one they dont put it there for nothing check these out your instructions should tell you how many ohms are required for your coil http://store.summitracing.com/default.asp?target=/egnsearch.asp&N=400122
You should be able to get a ballast resistor at Napa or other similar parts store. maybe even radio shack . Keep in mind that even with a ballast resistor keeping the key on may still burn up the coil or ballast resistor so hook your stereo up the right way. Or one of theses days you might not be so lucky and catch something on fire.
Not sure how hot the coil will get during normal operation but since its mounted to the engine and hot air flows over it from the radiator I would say it should be fairly close in temp to the rest of the componets under the hood.

 

[SeaBiscuit68]

Hi Meat. I'm curious why you don't have an accessory position in the ignition switch. That is so strange. Is it because the switch is a centech part? I'd be over to help you out but I have zero free time right now.

 

[meathead333]

Hi Meat. I'm curious why you don't have an accessory position in the ignition switch. That is so strange. Is it because the switch is a centech part? I'd be over to help you out but I have zero free time right now.

i dont know about the ignition thing, the acual ignition switch is aftermarket.

i just got done rewiring my stereo to my battery and it works fine. however, after about 15 mins of running the engine, the coil got pretty hot again. the guy at napa said hed move my coil off the block if he was me. the heat from the block may be heating the coil as well, i dont know. while i was rewiring the stereo, i found a bag of wires and misc spare spart the PO gave me. low and behold guess what i found....a ballast resistor. it looks pretty new. so now i am wondering if he took it out on purpose when he took out the points and put in the pertronix ignitor setup, or if he took it out by accident. does anyone know if i need a resistor with pertronix ignitor setup?