electrical issues

montyd

Member
Mar 13, 2006
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I got my car out for the first time in about a year. Its a 93 lx. And I had a charging issue so I pulled the alternator and it tested bad so I replaced it. Got the new one on and it still had a low reading on the gauge. O I turned the headlights on to see if the gauge would drop and it pegged so far down I couldn't see it any more. The temp gauge pegged way of past the top of the gauge and the tach dropped to pointing straight down. Turn the lights off and it all goes back too normal but low. Last year the firewall starter selenoid went bad and was causing the starter to run after the engine started. I replaced it and the starter and it fixed that problem. Any ideas?
 
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Bad or missing ground from the engine to the body. All grounds should be to clean shiny brght bare metal.

2.) The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges.

Any car that has a 3G or high output current alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects. The 3G has a 130 amp capacity, so you wire the power side with 4 gauge wire. It stands to reason that the ground side handles just as much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery , computer, & extra 3G alternator ground wire as described above in paragraph 2. A screwdriver points to the bolt that is the common ground point.

The battery common ground is a 10 gauge pigtail with the computer ground attached to it.
Picture courtesy timewarped1972
ground.jpg


Correct negative battery ground cable.
56567d1230679358-positive-negative-battery-cable-questions-86-93-mustang-oem-style-ground-cable.gif
 

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I know the ground wire is on the back of the intake and the firewall because I had issues with it sparking last year because it was loose. I'll start checking grounds and see what I find