Charging Problem !!

My son connected his new battery backwards. Went and got another battery put it in Correctly. Now it wont charge. I pulled the alternator and had it tested and checked out fine. Put it back together, Re connected all wires checking both grounds, and put on new terminals. What else could it be ?

He probably blew either a maxi-fuse or a fusible link somewhere. What year is the Taurus, and which engine does it have?

-Rod

If they say the alternator tested ok the first thing to check would be all fuses inside and under the hood in the fuse/relay center. There might be a diode plugged in there too. Look for a couple of fuseable links wrapped in the harness near the battery as well. Fully charge up the battery and notice the voltage with engine off and after it starts. Should be 14.0v or better if its charging.

I'm not sure what year they quit putting the external voltage regulator on the taurus, but if all else fails keep that in mind.

I dont believe there is a voltage reg. from everything I have researched. Are there any specific relays or fuses that would keep the battery from charging? I was told the PCM Might be messed up, but would it run fine like it does if that was the case? I checked the underhood relays but dont see anything suspicious with them. Hard to tell if ones bad by looking.

What year is the Taurus and which engine does it have? I can check the charging system wiring from the factory service manual.

-Rod

It is a 2002 SES 3.0 litre. And there is a separate box with 2 resistors in it next to the battery, dont know if thse are the ones or not. There is 4 more in the other fuse box under the hood, and about 3 in the car fuse box.

The box next to the battery has 2 resistors, or 2 large fuses? The charging system on the 2002 Taurus does not appear to have any fusible links or an external regulator. It looks like the likely suspects would be the 175A fuse located in the fuse block, or a 10A fuse number F1.26 in the Battery Junction Box.

-Rod

Thanks Rod, I will check those out. The box next to the battery has the 2 Black square 4 prong deals. I thought they were resistors.

All the mini fuses check out OK Hoping its the 175 amp mega fuse. Gotta make a trip to the good old parts store for that one. I will post results later.

The 175 amp mega fuse looks like the culprit. Replaced and ran the car with everything running and no battery light came on.

I'm glad to hear you got it resolved. Thank you for posting what you found.

-Rod