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Discussion Starter · #1 ·
Hey guys, on my car I run a Mallory Magnetic Breakerless Distributor. Now my problem is the magnetic pickup keeps burning out on mine. The past two weeks have seen 2 replacements and these things are not cheap!!!

Apart from that, I run an MSD 6a box and a Mallory coil.

Symptoms from the last two breaks;

1. RPM would fluctuate at 3,500 rpm before the engine just quit. Let it cool down for 10 minutes since my temp was getting up to 210 (aluminium radiator on the way!) before she just quit again. Bypassed MSD but I was SOL. Replaced the magnetic pickup and she started up again.

2. One week later took the car out for a spin, ran good, ran nice, parked for a couple hours and started up again no problem, but no more than 30 seconds later the RPM would fluctuate at 2,500 rpm and she just quit. Replaced the magnetic pick up again and she ran good.

Kinda scratching my head at this. Will a low voltage condition wreck a magnetic pick up? How about power surges?

Will one of these help?
Mallory Active Power Filter - Free Shipping on All Orders @ JEGS

Thanks!
 

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Discussion Starter · #3 ·
.
. Sounds like what you need... are you above using just a dependable HEI?
No not at all, but this is the distributor the car came with when I got it so it's what I'm using for the meantime. Been considering an HEI but the surge protector looks like it'll get thrown in my shopping cart for now.
 

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Hey guys, on my car I run a Mallory Magnetic Breakerless Distributor. Now my problem is the magnetic pickup keeps burning out on mine. The past two weeks have seen 2 replacements and these things are not cheap!!!

Apart from that, I run an MSD 6a box and a Mallory coil.

Symptoms from the last two breaks;

1. RPM would fluctuate at 3,500 rpm before the engine just quit. Let it cool down for 10 minutes since my temp was getting up to 210 (aluminium radiator on the way!) before she just quit again. Bypassed MSD but I was SOL. Replaced the magnetic pickup and she started up again.

2. One week later took the car out for a spin, ran good, ran nice, parked for a couple hours and started up again no problem, but no more than 30 seconds later the RPM would fluctuate at 2,500 rpm and she just quit. Replaced the magnetic pick up again and she ran good.

Kinda scratching my head at this. Will a low voltage condition wreck a magnetic pick up? How about power surges?

Will one of these help?
Mallory Active Power Filter - Free Shipping on All Orders @ JEGS

Thanks!
Sounds like a power issue either on the power or ground side. low voltage or bad connections will make the current go up and the magnetic coil is probably trying to absorb the additional current
 

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Mallory electronic distributors have a real problem with high voltage, and if your car has an alternator it will take out the module quickly. I'm surprised you got a new module more than once and didn't get anything in the packaging to mention installing protection ahead of the module to prevent burning them out.
Most alternators will put out over 13 vdc, and a Mallory module will fail at around 12.8 vdc or higher. There's several things you can do to eliminate the problem. You can simply put a ceramic ballast resistor ahead of the input power to the coil. Or you can install a Mallory Active Power Filter to protect it. Or you can wire in an MSD box, like a 6A, 6AL, etc. which limits voltage to protect the module.
Mallory distributors are a great product, but they shouldn't sell them without their Active Power Filter, as everyone who doesn't use one of the above fixes, will continually burn out the module. My 6AL box needed repair, so I wired in the $8 ceramic resistor ahead of the coil, while the MSD was being repaired. It was in the car for a couple months, and the engine ran great, and Mallory never had an issue either. It's the cheapest fix of the three I mentioned.
 

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Discussion Starter · #7 ·
Thanks a bunch for the replies, guys. Each one helps a lot.

I do have an MSD box there, right before a Mallory ignition coil. So, it's MSD box, Mallory coil, distributor. And yeah, nothing on the packaging of each module said I should put some surge protection, but I'm placing an order for one already as we speak.

Until the active power filter comes in, would it be best to put a resistor or the MSD box going into the distributor? Replacing these modules really hurts the wallet a lot.
 

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Thanks a bunch for the replies, guys. Each one helps a lot.

I do have an MSD box there, right before a Mallory ignition coil. So, it's MSD box, Mallory coil, distributor. And yeah, nothing on the packaging of each module said I should put some surge protection, but I'm placing an order for one already as we speak.

Until the active power filter comes in, would it be best to put a resistor or the MSD box going into the distributor? Replacing these modules really hurts the wallet a lot.
I'm a bit puzzled now, as the MSD box should protect the Mallory Unilite module. You didn't mention which Mallory distributor you had, so don't know if it's a single wire, or a Hall Effects type? If it's single wire, then you can put a old ballast resistor on the single wire input to the distributor. If it's a multi wire Hall Effects style, then I'd need to do some research before telling you where the ballast resistor should to be installed.
Mine is a single wire, so my MSD box is wired to the Mallory the same way as a MSD 6AL would wire to a points type distributor. MSD instructions are horrible, and don't mention the difference between various Mallory Unilite distributors, so they only show the one style, and don't mention that a one wire gets wired like a points setup.
I hope your MSD is wired correctly, and the filter is the only issue needed to fix the failing modules. If you happen to have a Mallory part number, and a diagram of how it's wired to the MSD box, it might help determine if wiring is an issue.
 

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Discussion Starter · #9 ·
Hi 1971, the Mallory distributor I have has the three wires coming out of it so I think it's the Hall Effects type you're referring to.

Not sure what the part number is, but I think that the distributor I have is the old Comp 9000 distributor 9648201. Looks like it matches the pictures on the net. Don't have the car with me at the moment since it's at my friend's garage waiting for an aluminum radiator.

EDIT
Also, I'm running a Mallory Promaster Coil, if that info helps.
 

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Hi 1971, the Mallory distributor I have has the three wires coming out of it so I think it's the Hall Effects type you're referring to.

Not sure what the part number is, but I think that the distributor I have is the old Comp 9000 distributor 9648201. Looks like it matches the pictures on the net. Don't have the car with me at the moment since it's at my friend's garage waiting for an aluminum radiator.
Yes, that's the Hall Effects style, and the Mallory active power filter should solve your problem. Not sure I'd install a ballast resistor in that style, as the leads are plug in, and the active filter is designed to plug right into the leads. So cutting and installing a ballast resistor will just kinda ugly up the wiring. I'd wait to drive it after the new power filter is installed.
 

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Hey guys, on my car I run a Mallory Magnetic Breakerless Distributor. Now my problem is the magnetic pickup keeps burning out on mine. The past two weeks have seen 2 replacements and these things are not cheap!!!

Apart from that, I run an MSD 6a box and a Mallory coil.

Symptoms from the last two breaks;

1. RPM would fluctuate at 3,500 rpm before the engine just quit. Let it cool down for 10 minutes since my temp was getting up to 210 (aluminium radiator on the way!) before she just quit again. Bypassed MSD but I was SOL. Replaced the magnetic pickup and she started up again.

2. One week later took the car out for a spin, ran good, ran nice, parked for a couple hours and started up again no problem, but no more than 30 seconds later the RPM would fluctuate at 2,500 rpm and she just quit. Replaced the magnetic pick up again and she ran good.

Kinda scratching my head at this. Will a low voltage condition wreck a magnetic pick up? How about power surges?

Will one of these help?
Mallory Active Power Filter - Free Shipping on All Orders @ JEGS

Thanks!
Common problem, the engine grounds aren't good enough for the high voltages involved. Unfortunatley once it it goes bonkers, it's gone. Following replacement part arrival include as part of the installation good solid grounds from each head to the chassis or back to the battery's ground stud. This can be number 10 stranded wire. Do not use thread lubricants or sealers on these connections, it needs solid dependable electrically bonded connections, lubricants and sealants are not good conductors. If this isn't sufficiently conductive the transient voltages on the ground side of the spark plugs will find a way to ground, problem is that may be through those expensive electronics.

This is not a starter ground circuit, that must also be there as this is a high amp circuit opposed to a high voltage circuit.

It really doesn't hurt to ground the rear axle, transmission, engine block close to the starter and another close to or from the alternator bracket, and the heads maybe from more than one location when running a high energy ignition.

Bogie
 

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Common problem, the engine grounds aren't good enough for the high voltages involved. Unfortunatley once it it goes bonkers, it's gone. Following replacement part arrival include as part of the installation good solid grounds from each head to the chassis or back to the battery's ground stud. This can be number 10 stranded wire. Do not use thread lubricants or sealers on these connections, it needs solid dependable electrically bonded connections, lubricants and sealants are not good conductors. If this isn't sufficiently conductive the transient voltages on the ground side of the spark plugs will find a way to ground, problem is that may be through those expensive electronics.

This is not a starter ground circuit, that must also be there as this is a high amp circuit opposed to a high voltage circuit.

It really doesn't hurt to ground the rear axle, transmission, engine block close to the starter and another close to or from the alternator bracket, and the heads maybe from more than one location when running a high energy ignition.

Bogie
A good ground circuit is always a great idea, but it wont stop the Mallory Unilite from burning up modules. Mine had a heavy #4 ground cable to the head, and the Mallory still went. The filter, or ballast resistor is the only thing that will clip voltage and stop them from frying.
 

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Discussion Starter · #13 ·
Thanks for all the helpful replies, guys. You learn something new everyday! Looks like I'll be putting that resistor in and additional groundings on my engine.
 
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