Electrical short?? 97 Infiniti I30

[keywester]

The car loses electrical power, when there is a load on the system. Mostly when I apply the brakes, at night with the headlights on. I notice the headlights dimming, and the engine idles a little bit rough. When I turn the car off, the security light flashes very quickly, and then loses power. If I try to start it up again, I get no power. If I open the hood and wiggle the Negative battery wire, the power will come on. I have replaced the alternator, and belts, the battery is brand new (750cca). I had a test done at a local Advance auto, and everything came back ok. I am no ace mechanic. I can usually figure things out, but if it involves electrical, I am lost. Any advice would be appreciated. Thank you in advance.

[loystock]

Welcome to NICO.

Check/clean the battery connectors and check the battery cables for corrosion. Replace corroded cables. Check the connections and wiring coming from the alternator as it is possible to 'cross' a 'hot' wire to a ground wire (stripped insulation). Check the security of the ground connection as well the battery wire going to the fusible links and relays. A good and fully charged battery must have 12.6VDC or higher. Also, what is the charging voltage from the new alternator? It must be >13.8VDC (spec is 14.1-14.7.) and steady (no fluctuation).

If all of the above are OK, you may have a partial short somewhere. You need an Ammeter and then pull one fuse at a time to isolate.

Let me know if you can read wiring/schematic diagrams.

[keywester]

Thank you for the reply. I will check all that you listed and let you know. I am not that familiar with schematics. I had a mechanic, who had schematics for this vehicle look at it. Paid him $200 bucks, and he said that there was a bunch of loose connections, and such. Worked fine for about a week, then started giving me problems again.