I was hoping someone might be able to help me figure out whats going on, my ignition module seems to burn out every 3 to 8 mo's. I have a 94 full size blazer with a 5.7, I have an accel billet distributor, matching accel coil, plugs and wires. I have replaced the battery to engine ground with a new 4 gauge wire with pigtail ground to the fender(4 mos ago) and replaced the alt output wire with the same (minus the pigtail ground-LOL). The engine to chassis to body ground wires (pass side) are in place and seem to be in good order. Are there other grounds I should be checking? Should I maybe run a ground from the dist hold down to the engine ground from the battery? I have checked the wires from the dist to module, no chaffing....the module to coil, no chaffing and the module to wire loom and couldn't see any problems but I did not open up the loom. Any help would be appreciated as this is a major PITA, I just had to replace my 4th in less than a year yesterday.

I know Accel isn't the best parts manufacturer but I'm stuck with it until I can find a new job and replace it. I THINK its the ignition module since the vehicle starts and runs fine after I replace it, maybe could be something else and I'm just throwing money away?

 

putting dielectric grease on the mounting surface of the ignition module might help if you havent been doing that. \

years ago i had a older k5 blazer with the HEI set up where the coil goes on top of the distributor and had the same issue. maybe eveyr 2-3 months it would just randomly die. i even kept a few in my glove box so i could fix it on the side of the road. finally figured it out as it was one of the wires that went from the distributor was slightly cut and arching to the ground.

you have a different set up but might be similar. try feeling around the coil and distributor and see if you get zapped at all.

 

You actually need to use thermal paste, you can buy a small tube a radio shack for a few bucks, does about the same as dielectric i guess, just made specifically for heat transfer. I had an 84 V8 S10 pickup that was real hot under the hood, I fryed about 4 of em before....get this, an "intelligent" parts guy told me to use thermal paste, never had another problem. Go into radioshack and tell them you need thermal paste, theres some more expensive stuff but the cheap stuff will do the trick. Parts store may even have it in those little packets at the counter.

 

Thanks for the responses, I did put on the dielectric grease that came with the parts (white greasy stuff) but I will deffinately try the thermal paste, can't hurt.

Thanks again!

 

White greasy stuff probably was the same as thermal paste. Look up a wiring diagram for your specific distributor, some distributors/ignition modules are supposed to run a resistor in line with the ignition coil+ wire to reduce strain on the module, the reason ignition modules creat heat and fail is because of the transistor inside that is constantly switching the ground on and off to the coil, another good thing to do is call accels tech hotline if they have one, they know their Products best and should be able to help diagnose any known issues.

 

Well, I installed a new Pertronix dizzy and coil and sho nuff.....ignition module failed after just a few weeks. Put in an old Summit module and it fired right up.I put thermal grease on the new dizzy module and it obviously didn't help. Banging my head against the wall is REALLY starting to hurt and leave a mark. I have way too much time and money invested in this to just walk away and get a new truck plus I like where this one is goin.

Dime......Looked up the wiring diagram and did not see where the resistor would be in line for my engine, thanks for the advice tho....

 

Do you have and aftermarket tachometer connected? If so unhook it and see if it lasts longer, could be feedback into the circuit? Ignition modules are transistorized circuits, there are 2 main things that transistors dont like, heat and voltage spikes, the coil can send return voltage spikes into the module but you changed that too. A cheap thing to try would be take your alternator in and have it tested, a bad diode can potentially a0 voltage which could hurt the module. I think in alternator test specs this is called ripple current. I hope you figure this one out soon!

 

No aftermarket tach, although the tack test lead is just taped to the wiring harness, looks factory. Alternator is newer, did a 160 amp upgrade because of the added electricals I have but the problem has existed since before that was installed and persisted since. Really appreciate the ideas, helps me think outside the box and look around harder at things.

 

Are you running the "stock style" ignition setup and throttle body injection through the factory '94 computer?

 

Yes, all factory other than bolt ons. UPDATE!!! I must be a dumbsh*t because for whatever reason I decided to put my "burned out" ign module back in just for sh*ts n giggles and sho nuff.....started right up numerous times. DOH!!

So now what? I am thinking maybe a sometimes issue in the ignition switch? or is there an ignition relay somewhere that could be an issue? I looked in my Hanes manual at the wiring diagrams and didn't see a relay but just 'cause I didn't see one doesnt mean it ain't there. Plus Haynes aren't known for being perfect. Sorry about wasteing yer brain power on "why is module burning out" b.s. just because I was too dumb to get a module checked out.