Your power wire from the battery going to your starter is probably grounding on the frame, starter, or block. That's why the issue is intermittent. It's a short to ground. Get a bright flashlight in the dark go look closely from under the truck to find where the wire is grounding. Move the wire around a little to see where it could be swinging or bouncing to touch, then if nothing looks the culprit at the cable line, check it's connection to the starter to see if it is frayed and grounding out at the terminal.
You'll find this short a lot easier to find at night as it is likely to be sparking when it happens. Keep your hands away from the belts and fan, start the engine from dead cold, and shake all the wiring around if you are not successful at first inspecting the main power wire all the way back to the starter.
The reason it is a short to ground is because the only way to intermittently drop the voltage and still pass the alternator test is by a short that comes and goes when you bounce over something and start the grounding process.
----------
Quote:
Originally Posted by 98rangerxlt
When you tested the battery voltage, was it with or without the vehicle running. A good battery, fully charged should not drop below 9.6 volts when cranking.
|
It will, if the cable is shorting to the frame. That's why the battery performs properly SOMETIMES. Batteries don't come and go on voltage as we know. Once they drop, they are dead until recharged. This battery worked intermittently as did the alt. It was never dead, it was being drug down from high amps. It's also why the truck stalls while at idle. The ignition voltage drops from the short.
----------
Quote:
Originally Posted by FireRanger
The IAC is not going to cause the battery to die. The engine is dying due to low voltage.
|
On the right track.
