1995 mustang gt voltage issues

ozzman306

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I have a 1995 mustang gt. Stock car with a v3 Vortech (6psi).... I’ve owned the car for 12yrs purchased it from original owner ...I’m having a voltage issues. Here is a list of things that I’ve already replaced or have done !!

New alternator

New Battery

New Positive and negative wires

New Starter wire

New Ground straps to the block

Checked dash for cut wires and engine compartment . Everything looks fine

I’ve scanned my car for codes nothing comes up. my PCM passes according to my craftsman scanner !! Help this is driving me nuts




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Blkkbgt

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Can you elaborate more on your specific issues? Is the battery draining? Is the car dying at random times?

Without any additional information all I can think of at this point is to check the alternator and starter wiring harness. There are 2 brackets that hang off the bottom of the timing cover and they pinch the wiring harness. This is a common spot to have issues because the idiots who did the assembly almost always crush the wire. After years of vibration eventually the shitty plastic loom wears through and then the insulation around the wire goes.
 

ozzman306

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Battery drains after sitting for a week . I removed the aftermarket alarm yesterday so not sure if the alarm was the draining issue .

When I drive the car it bucks here and there but only at cruising speeds between 15-45 mph. car is reliable doesn’t die I’ve driven it 150 miles to the track raced it and drove it back home another 150 miles...car passes (California) smog all the time. car does idle low at times and is shaky


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ozzman306

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One more thing the cooling fans never turn off . I did retrieve 2 codes after driving the car p0420 could be because I’m running a off road X-pipe I have new o2s

DTC:564
P0420


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ozzman306

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Can you elaborate more on your specific issues? Is the battery draining? Is the car dying at random times?

Without any additional information all I can think of at this point is to check the alternator and starter wiring harness. There are 2 brackets that hang off the bottom of the timing cover and they pinch the wiring harness. This is a common spot to have issues because the idiots who did the assembly almost always crush the wire. After years of vibration eventually the shitty plastic loom wears through and then the insulation around the wire goes.

....


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Blkkbgt

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I would have started with the alarm as well. The problems with them usually are usually related to bad installations though.

From there I would start doing some parasitic drain testing with a multi meter. There are plenty videos on youtube you can watch to learn how to do this.
 

Blkkbgt

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One more thing the cooling fans never turn off . I did retrieve 2 codes after driving the car p0420 could be because I’m running a off road X-pipe I have new o2s

DTC:564
P0420


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Those codes mean nothing in this situation because like you said you're running an off road x.

The fans never turning off is kind of interesting but I doubt this is your issue. I wouldn't be surprised if your tune has them turned on all the time. Now if they were on after you shut the car off then I would look there obviously.
 

Slow 99

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are you running underdrive pullies? cause if so, the alternator wouldnt charge as much while driving as opposed to regular pulleys. as for the fans, it isnt uncommon for the fans to be on most of the time but check coolant level and try and bleed your system of any air bubbles. don't worry about the codes though
 

ozzman306

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are you running underdrive pullies? cause if so, the alternator wouldnt charge as much while driving as opposed to regular pulleys. as for the fans, it isnt uncommon for the fans to be on most of the time but check coolant level and try and bleed your system of any air bubbles. don't worry about the codes though

My car doesn’t have underdrive pulleys. I fixed fan issue tho. my car had an old a hypertech chip!! Dates back to 1996 lol ... I removed it fans cycle on and off now but car still have the voltage issue :-(


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Slow 99

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My car doesn’t have underdrive pulleys. I fixed fan issue tho. my car had an old a hypertech chip!! Dates back to 1996 lol ... I removed it fans cycle on and off now but car still have the voltage issue :-(


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I would try buying a tuff stuff alternator, I have one and it clears my procharger’s 6 rib pulley with room to spare with a little bit of sanding to the case (depending on application) and I run high 14 volts when my car is turned on and it never runs out. Also check to see if you have a piggy packed fuse used for your audio system or something like that because that can also drain your battery over time


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ozzman306

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I’m gonna check my timing and other things as well. I’m kinda thinking my IAC valve is causing my bad idle. this car has all original sensors minus the O2s ... I’m thinking the idle being bad is making my voltage fluctuate.. car always maintains 14+ volts with all accessories on


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