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Ford Taurus electrical problem?

So I’m new here, not sure if this is where I ask questions lol

But I drive a 2003 Taurus & im having a problem with my car stalling at times.

The main problem is, that whenever I’m driving on the road, I hear a “pop” sound, sounds like it comes from my speakers.
But whenever I hear that “pop” sound, all the lights on my dash turn on & my car “turns off” or the engine seems to stall for like a split second making my car jitter really bad.
At times, just by rolling my windows up or down, the car turns off completely, but I can easily turn it back on.

I don’t have AC on my vehicle but whenever I turn on just the fan air, my vehicle seems to do it way more often, I’ve checked for vaccum leaks but didn’t find any, my battery and terminals are good, could it maybe be a bad relay?

Also, my radio seems to not function properly at times, for instance sometimes I can’t change the bass or treble but I can higher/lower the volume & shut it off.

I’m not much of a car expert, but I do need help here guys.

You state that your 2003 Taurus doesn’t have AC.

Is this a fleet vehicle?

Because a 2003 Taurus came with AC as standard equipment.


it seems that problem is directly connected to the electrical load

first, I would touch nothing and make sure problem can be reproduced easily, at will, for example turning on rear window defroster, lights and operating windows

I could guess that your ignition switch has worn contacts on “ignition” circuit, which holds all the consumers working when car is running and likely you would be able to see a “sag” in voltage if you use multimeter as you use your “reliable problem reproduction procedure”

pay attention that a lot of cars nowadays have two ignition circuits, operated simultaneously, you would want to test all of them

here is your car wiring for aftermarket alarm hookup:

as you see, you would look for:

Vehicle Ignition Wire (+): Red/Light Green
Vehicle Ignition Wire Location: Ignition Switch Harness

Vehicle Second Ignition Wire (+): Gray/Yellow
Vehicle Second Ignition Wire Location: Ignition Switch Harness
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@sixfigureentrepreneur (inafourteenyear-oldcar)

Have you made those 6 figures, yet? If not, I’d start with the easiest and cheapest things first.

I’d start by disconnecting the battery cables from the battery and cleaning them and the battery terminals before reconnecting them.

How old is the battery? Have you considered taking to an auto parts store or someplace that will test the battery/charging system free of charge?

I, too, am intrigued by the idea of No A/C.

Did the car not come with air conditioning? or is the a/c just not functional, but the parts are still there?

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lol I sell cars & I just got his Taurus from the auction a month ago & im having the issues right now, never have I encountered it that’s why I made an account here and ask for advice :upside_down_face:

The battery is 2 years old & ive gotten it tested & works fine, the terminals are clean also.

The car has no AC due to freon leak that’s all.

No AC due to freon leak that’s what I meant, sorry lol

You buy cars at auction to sell and you don’t have a mechanic on speed dial?

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I’m 23 years old, starting my own business on the low-low I’m not highly experience, sorry if I’m not an expert like you. I do everything myself…

As others have stated earlier there is an intermittent power connection in the wiring to the ignition system of the engine somewhere. There should be some fuses in the dash fuse panel that supply power to the ignition system. You could check the power at the fuses to see if there is a problem before the fuses.

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Thank you for your answer, I will sure check on that, much appreciate it.
God bless.

You’re welcome for the help.

The trouble could be a bad connection at the battery but that would mean all the accessories would be intermittent. You should see things like the headlights flash briefly or other things not tied to the ignition circuit. The dash warning lights are tied to it. It wouldn’t hurt to go over the battery connections at least just to make sure things are good there. Also check the chassis ground connection to the battery. If you suspect the trouble is beyond the battery then tapping on suspected areas like the power panel under the hood and the ignition switch with a screwdriver handle might show up something.

I agree that you need to thoroughly clean all of the battery cable ends and battery posts.

If not that, I’m wondering about the electrical part of the ignition switch. There was an electrical engineering flaw (in my opinion) on some Ford vehicles and that includes the Taurus and Sable.

The current to operate the cabin blower motor is routed directly through the ignition switch. This is a high current (meaning a lot…) item that only increases with age. Over time and miles the current draw can burn the contacts in the ignition switch and even melt the switch housing.

I had this problem twice with my old Sable before figuring out what the root cause was. On my car (after the second switch replacement) I added an additional relay and routed the blower motor current through that so it would bypass the ignition switch. Never a problem again. So maybe turning on the fan is what exacerbates the problem.

The switch is cheap but the column needs to be dropped and there are anti-theft bolts that have to be drilled out so the switch can be removed.
Hope that helps and good luck.

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You may have to leave it with a shop and ask one of their tech drive it to and from the job. Eventually this symptom will occur and the tech will have the equipment with them to figure out the cause. If I had this problem on my own car I’d hook up some wires from the engine compartment into the passenger compartment and monitor the voltages with a volt meter to see if something goes askew with the voltage when this happens. Battery voltage, ignition module voltage, alternator output voltage, etc. Eventually I’d catch it.

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I wonder about the other ends of the cables, opposite the battery terminal ends. It’s easy to throw a jumper cable on the negative terminal of the battery and attach it to a good clean “ground” and try it. That provides a secondary ground in case the regular one is faulty. If it “fixes” the car then you know where to look.

I would be careful not to disturb the problem until root cause is identified, as doing so can mask it and make less frequent to reappear.

For this particular case: need to find a circuit where it is a positive correlation between the problem observed and voltage sag.

Ideal case would be to find a cable or circuit where it is +13V incoming and +7V outgoing under overload condition for example.

It would be unlikely to point a finger at the sky and find one, so “working back on the electricity flow chain” can help:

  • Ultimately, it is ECM/ECU who [presumably] gets a sag in power: find a circuit feeding ECU (upstream fuse would be probably the easiest to tap) and check that under “let’s use overload to reproduce the issue” voltage there really sags
  • if sag found -> go to circuit feeding this fuse, presumably ignition switch: check it there and an upstream feeding source, which is likely to go to “master fuse” on the battery terminal
  • if sag is found on an upstream of ignition switch -> go and check on that moderately thick cable going to master-fuse-block on battery terminal
  • etc…

I do not have Ford Taurus circuitry sheets, but I was able to find one for my Pathfinder very easily on, so I can imagine if OP looks over Internet for Ford forums, he can find one and then this problem gets switched from the “mystery” into a methodological 1-2-3-… search

I have my own bet on the ignition switch, as it is the likely WEARABLE item, but I can be wrong

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I would unhook the power to the A/C compressor. It could be that the compressor is trying to engage, but is in the process of locking up- causing your issues (especially when you mention that the problem gets worse when you turn the fan on.)
This may not be the fix, but that is where I would start.


I had a stalling problem similar to this years ago w/my VW Rabbit. That one turned out to be a problem inside the fuse/relay box. The problems was not visible unless you cracked the plastic covered fuse box open with a hammer and took it apart. Which curious me did of course …lol … One of the metal bus bars had overheated and it’s connection to another bus bar carbonized and failed, causing an intermittent fuel pump power problem. Not saying this is the OP’s problem, but noting that it might be difficult to solve by the parts replacement guess method. Probably will take some significant diagnostic work. On the upside, once the cause is found it will probably be fairly simple to fix.

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Classic signs of a bad ground if operation of electric stuff makes the engine stall. Even if the negative battery cable looks good, change it. Testing this may be easy with a test cable from engine to fender. Install one and the problem may vanish. Then you can fix it, hopefully. Then the brushes in the alternator may be really worn.

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