wiring - tach doesn't work with lights on!?!?

  • I torn down my compartment to detail on the '65, and when I did, I took careful pics of all the wiring and labled everything. At some point, a PO put in a GT style dash cluster (removed the falcon stuff), and the Shelby pod, complete with mechanical oil pressure and Sun tach. There were a few wires that weren't connected to anything in the bay when dissasembling, so they were marked, terminated and taped up out of the way. Now that everything is back together, everything works fine, except when I turn on the headlights. The headlights work fine, but then the tach bottoms out to zero, and I don't have the light in the pod either. I've double and triple checked all my connections at the solenoid, alternator and coil and all match the pics I documented prior to dissasembly. I cleaned the ground area at the firewall and the block where the negative battery cable goes. The other day, I removed all the wraping/tape from the unused wired I bundled together, terminated the ends with more tape, and layed them out so they weren't crossing or anything. Still the same.


    I also noticed that my positive battery cable (new) turned BLACK at the battery post. WTF??. There is also some corrosion at the tightening nuts there. My freshly painted battery tray also showed signs of battery leakage. I will replace the battery, but I worry something else is wrong, which is causing these problems. Any ideas? I found the fuse box, but can't figure out that archaic dusty fixture. Does this sound like possible fuse issue?


    Thanks for any assistance!


    Troy

  • It sounds like the tach/pod light is looking for a ground path. I would isolate that circuit and see what happens.


    As far as the battery, is it overcharging? That may make acid boil over. Or maybe the battery just has a bad cell and it has nothing to do with your work.


    Edited by - 289kford on 04/17/2009 09:43:22

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