Electrical short?

JasonNC
JasonNC Expert Adviser
I installed the Autowire 15 wiring harness in the 49 Super Six, and it appeared to be working fine until I took the car off the jack stands.  Now, the fuse that is connected to the instrument panel keeps blowing and if I drive the car out of the neighborhood and stop, it won't crank for a minute or so.  It will click like the battery is dead, but after a short period will crank.  I modified the wiring harness slightly because I wanted to use the original key switch.  There is a wire that goes from the alternator back to the Autowire ignition switch that I did not attach to the Hudson switch, but the alternator was charging. This probably a problem that only I created, but I'm hoping somebody might have an idea as to what I did wrong.  

Comments

  • bob ward
    bob ward Senior Contributor
    One method of fault finding is to connect a lightbulb across the fuse that keeps blowing. The bulb lights up because you have a circuit from the battery to the bulb and back to the battery via the short. Keep disconnecting wires until the bulb goes out.
  • Double and triple check grounding.
    also make sure no shorts with the wiring on the effected circuits.
    take it you have checked all the wires are feeding to the correct places on your fuse block.

    Fuses blow soon as you load power to the ON possition or once you start trying to crank?
    Get a voltmeter and check the readings. Do this at the point the circuit is trying to give power to. ie if its a light circuit then you would test at the light.
    if you dont have a voltmeter use a test 12volt test light.

    Checking the circuit thats blowing the fuse first. make sure no shorts.
    Check your end connections you made up. make sure no exposed wires and they are  not touching anything that will earth them.
    Its happening in the  "on" and "Acc" position on the ignition?
    Hudson even have ACC  for that matter? If so that should be the place you attach the alternator wire from memory.

    But yeah check your grounding. make sure its not on paint etc. even unbolt it and attach it to a known good ground and try.

    those kits are well made so i would imagine its an install issue relating to grounding or to connectors shorting or wires rubbing due to no grommets and shorting going through the firewall etc.

    Alex
  • forgot to mention if you are still points test your ballast resistor and coil as well.

    Maybe just replace the resistor.

    Alex
  • JasonNC
    JasonNC Expert Adviser
    The fuse blows as soon as the key is switched on.  There is a wire from the alternator #1 terminal that I didn't hook up to the original ignition switch because the Highway 15 instructions called for it to be attached to "accessory" post on the ignition, which my original ignition switch does not have. This wire also had the option of installing a diode as part of the wiring instructions.  I plan to call American Autowire tomorrow to see if they can help as well as follow the advice that has been offered by you guys.  
  • if it blows as soon as power has been added to the circuit and your sure you have it wired to the correct slot on the fuse box with the correct fuse then it points towards you having a short.
    A wire on that circuit has metal exposed somewhere and its touching some form of ground. This normally happens at the wire ends. Mostly at what ever form of fastener the user attaches. Did you add rubber grommets at the places wires go through the fire wall?
    If you have shrink fit then put this at the wire ends to help insulate.

    When im back from work i will get out my AAW Highway 22 kit and take a look. its still in the box with bags unopened. The components and kit looks nice and heavy. well made kit.
    Thought you guys in the states had Memorial day tomorrow? AAW might be closed.

    Alex
  • JasonNC
    JasonNC Expert Adviser
    True.  They probably will be closed as well as Radio Shack, etc.