Ignition ballast resistor or resistance wire ?

Discussion in '1960-1966' started by Jonnygogo, Dec 13, 2009.

  1. Jonnygogo

    Jonnygogo Member

    Joined:
    Sep 20, 2009
    Messages:
    41
    Location:
    Brooklyn, WI
    1963 C10 w/292; I am planning to replace the distributor with a Mallory Unilite pointless distributor the instructions emphasize the necessity of either a ballast resistor or a loom resistance wire between the ignition switch and the coil. I didn't see anything like a ballast resistor but it could be under the dash. Does anyone know if these motors came stock with one or the other?
    Thanks, Jon
     
  2. markeb01

    markeb01 Member

    Joined:
    Sep 29, 2009
    Messages:
    168
    Location:
    Spokane, WA
    Here’s the link to a stock resistor. It appears they were used through 1959. On all stock installations I've seen it's usually mounted on the firewall near the coil.

    http://www.classicparts.com/1947-59-Ignition-Resistor/productinfo/53-911/

    Here is the Mallory offering. If you’re going to use the Unilite, I’d recommend going with the Mallory resistor since I think the resistance is different from a stock Chevy.

    http://www.summitracing.com/parts/MAA-700/

    If you haven’t purchased the Mallory distributor yet, I’d highly recommend doing a Google search on Mallory Unilite problems, resistor, troubleshooting, etc. There are a lot of threads covering problems with this ignition. I had one about 20 years ago and spent many months replacing almost everything in my engine trying to figure out why it ran so badly. I casually mentioned it to a racing buddy, and he immediately recommended I junk the Unilite and give the module to someone that raced with them, since they fail all the time.

    I immediately switched to a stock HEI and have never had a bit of trouble since. Some web threads seem to indicate the newer models are better than the early versions, but if it were my money I’d do something else.

    It seems the MSD system is most popular with racers, and for street driven vehicles the answer is either a Pertronix kit, or a stock replacement HEI. Both the Pertronix and HEI are completely reliable. The Pertronix is often preferred in V8 applications because it fits under the stock cap and retains the original appearance. I believe the following link is for the correct kit for a 292 Chevy, but this should be confirmed before spending money, if this option is of any interest.

    http://www.summitracing.com/parts/PNX-1162A/
     
  3. LittleStar

    LittleStar Member

    Joined:
    Dec 7, 2007
    Messages:
    30
    Location:
    SOCAL
    I've been using a MSD 6AL box with a MSD distributor in a street driven car for years and have found it to be completely reliable. I replaced a Unilite piece of junk with this system.
     
  4. Jonnygogo

    Jonnygogo Member

    Joined:
    Sep 20, 2009
    Messages:
    41
    Location:
    Brooklyn, WI
    I should have checked here first.

    That is two bad reviews of the Unilite. I should have my intentions by the forum BEFORE I bought the darn thing. I have not installed it ... yet. I could return it to Amazon and get the MSD system. I just want a good reliable pointless system for the street.

    Does anyone have anything good to say about the Mallory distributor? Thanks.
     
  5. Rich 5150 69

    Rich 5150 69 Member

    Joined:
    Oct 1, 2008
    Messages:
    334
    Location:
    Nor Cal
    If you follow the wiring directions its not a problem, biggest issue is ground it to the motor, ensure it will never come loose as it will blow the eye, I`ve got one in two vehicles, the oldest is going on eight years the other is five years never had a problem...;)
     
  6. LEYLAND

    LEYLAND Member

    Joined:
    Aug 2, 2006
    Messages:
    229
    Location:
    Ontario, Canada
    I also purchased a mallory to replace my points distributor but I never used it... changed to the MSD HEI, hopes to future upgrade to 6AL box!

    I recall selling it at the swap meet:cool:
     
  7. drabo

    drabo Member

    Joined:
    Jun 9, 2003
    Messages:
    759
    Location:
    Patrick AFB, Florida
    I use a Mallory Unilite in my 66. You must use a ballast resistor or you will burn up the optical eye. I bolted mine right under the coil to kind of hide it. Also it is recommended that you use a filter between the coil and the distrubutor or you run the risk of damaging the module. I had a OEM type of regulator go out of adjustment and it sent a voltage spike through my distributor and fried the module. Other than that I have had no problems with my Mallory. The old girl would fire up in -22 in Alaska just as fast as 90 in Florida.

    http://www.amazon.com/Mallory-29351..._1?ie=UTF8&s=automotive&qid=1261063661&sr=8-1
     
  8. Jonnygogo

    Jonnygogo Member

    Joined:
    Sep 20, 2009
    Messages:
    41
    Location:
    Brooklyn, WI
    Thanks guys

    I think I will try it with the ballast resistor and filter.

    Drabo: thanks for the link. I ordered the resistor and filter and hope to get it all installed in a week or so. Will apprise.

    Thanks again.
     
    Last edited: Dec 17, 2009
  9. 66 KUSTOM

    66 KUSTOM Member

    Joined:
    Jan 11, 2005
    Messages:
    624
    Location:
    SALEM OR
    The original wire is a resistance wire. I removed it with my Mallory HEI so i get 12v.
     
    Last edited: Dec 17, 2009
  10. drabo

    drabo Member

    Joined:
    Jun 9, 2003
    Messages:
    759
    Location:
    Patrick AFB, Florida
    Also if you do any welding on your truck you must unplug the distributor.
     
  11. Jonnygogo

    Jonnygogo Member

    Joined:
    Sep 20, 2009
    Messages:
    41
    Location:
    Brooklyn, WI
    Is ballast resistor necessary if there is a resistance wire?

    I am almost positive that the wiring harness under the hood is stock. If my truck has a resistance wire between ignition switch and coil is the ballast resistor necessary? Can I install it in addition to the resistance wire?

    Thanks for the tip about welding!
     
  12. drabo

    drabo Member

    Joined:
    Jun 9, 2003
    Messages:
    759
    Location:
    Patrick AFB, Florida
    Check that wire for voltage. The resistance is used to reduce voltage in a DC circuit so that being said it should be lower than the voltage at the battery if it has resistive wiring.
     
  13. markeb01

    markeb01 Member

    Joined:
    Sep 29, 2009
    Messages:
    168
    Location:
    Spokane, WA
    If it were mine, I wouldn't take any chances with the existing wire. I'd run a new wire from the ignition to the coil, along with the resisitor designed for the ignition. That way you're eliminating variables that could possibly toast the new and expensive system.
     
  14. 66 KUSTOM

    66 KUSTOM Member

    Joined:
    Jan 11, 2005
    Messages:
    624
    Location:
    SALEM OR
    I completly agree, i replaced all the wiring in my truck with wiring from our hosts here. I did do some modifications to fit my hot rodding needs but they sell very good color matching harnesses here for very reasonable prices.
     

Share This Page