95 Mustang GT new battery dying over night any ideas of the cause

[Black95]

Hi I have a 95 Mustang GT with a brand new battery installed and if the car sits for more than a day the battery is completely dead but if I starr the car everyday even for 5 minutes it's fine the following day, I thought at first could be the cables but then would it not hold the charge then thought alternator but it's charging the battery any help will be greatly appreciated oh one other thing temperature gauge not working an wouldn't turn the fan on not sure what parts are needed to get it working again

 

[evilcw311]

Does it have an aftermarket alarm??
Does it have the mach460 stereo??


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[Black95]

Aftermarket alarm was removed no Mach 460 stereo

 

[white95]

Does it have an aftermarket alarm??
Does it have the mach460 stereo??


Sent from my iPhone using Tapatalk

Wonder if he’s having CCRM issues since the fan relays are in it.

 

[ttocs]

Just for shits and giggles go into the drivers side console. Pull the carpet down below the plastic right next to the gas peddle and peek in and see if you see a silver box with a bunch of holes in it and two harnesses. We are asking about the mach system because the amps have been a known current drain for some time. There is actually a version between the mach/standard that still has the small amp/cross over up front and it it is still plugged in then disconnect it.

Are you sure there is no alarm in it or you just were never told? Its not uncommon for dealerships to just not give the remote to the system rather than pull the entire thing so it will not be their problem later. While you have your head by the gas pedal look up into the dash and see if you see any extra wiring.

Now if all of these come up empty the next step is to get out your amp/multimeter. Disconnect the battery(either side) and then connect your amp meter in between the disconnected battery. Now look at the reading of how many amps are being pulled, and then start pulling one fuse at a time from the fuse box. At some point you will see the current drop sharply with one fuse and from there we can narrow down what might be in that circuit.

 

[Black95]

Ok

Just for shits and giggles go into the drivers side console. Pull the carpet down below the plastic right next to the gas peddle and peek in and see if you see a silver box with a bunch of holes in it and two harnesses. We are asking about the mach system because the amps have been a known current drain for some time. There is actually a version between the mach/standard that still has the small amp/cross over up front and it it is still plugged in then disconnect it.

Are you sure there is no alarm in it or you just were never told? Its not uncommon for dealerships to just not give the remote to the system rather than pull the entire thing so it will not be their problem later. While you have your head by the gas pedal look up into the dash and see if you see any extra wiring.

Now if all of these come up empty the next step is to get out your amp/multimeter. Disconnect the battery(either side) and then connect your amp meter in between the disconnected battery. Now look at the reading of how many amps are being pulled, and then start pulling one fuse at a time from the fuse box. At some point you will see the current drop sharply with one fuse and from there we can narrow down what might be in that circuit.

Will do just has to wait a few weeks currently fighting Covid thank you, as for the alarm my son took out the aftermarket one

 

[ttocs]

it sounds like a lot, but the actual time under the hood is pretty minimal. Now after we figure out what circuit it can take a little time to find the actual source.

 

[dcm0123]

Had a bad Ford alternator which did this. Recharge the battery, re-connect the cables and see if you feel the alternator heating up. Could be an internal short. Another option is charge the battery and unplug the alternator to see if the battery still dies over night.

Have you tried to pull each fuse and use a light across the terminals the fuses plug into to find out what is drawing current when the car is off? Do the same with plug in circuit breakers if you find any.

I believe you will find a fuse block inside the car as well as under the hood on left inner fender.

You may also want to put the new battery on a tester to verify it is not defective.

Try unplugging the fan control box (power train control module) mountdr next to your radiator overflow tank and see if the battery goes dead overnight. They are known to have problems and could have shorted inside. The high current from the fan causes the relay and other components to burn up inside. Is probably reason you cooling engine fan does not work.

https://www.rockauto.com/en/moreinfo.php?pk=944041&cc=1134188&jsn=501

The engine fan is turned on by the engine computer temperature sensor. It closes a relay in the above box which puts power to the fan. The gauge temperature sensor is a separate sensor which I believe is mounted towards the drivers side rear of the intake manifold. If your engine computer temperature sensor was bad, the engine would not run (or run very poor)

Look up the temperature sensors on Rockauto under the cooling section. The gauge sensor is shown with a threaded stud on the top which the wire connects to. The engine coolant sensor has a plastic plug connector on the top of it.

 

[Wmac]

The temp gauge sending unit is located in the front left corner of intake manifold, not the rear. Check the wiring connector at the fan. There was a recall about 20 years ago concerning wires melting at the fan connection.
Also when in eec test mode, both fan speeds are checked momentarily.

 

[dcm0123]

The temp gauge sending unit is located in the front left corner of intake manifold, not the rear. Check the wiring connector at the fan. There was a recall about 20 years ago concerning wires melting at the fan connection.
Also when in eec test mode, both fan speeds are checked momentarily.

Thank you for the correction- I have a trickflow head/intake setup and this is where mine ended up.