battery warning light is on

[jasminegasca]

So I took my car in to get my coolant leak and my oil leak fixed, great they fixed it but they called me telling me my battery warning light came on. They tested my battery its fine they tested my alternator and said that was the issue. So i had my friend swap it out. We swapped it and to my dismay the warning light turned back on. We thought on maybe we got a faulty alternator we went back swapped it out and still the warning light is on. So my question is what could be wrong if the alternator is new and the battery is still good.

 

[jlee]

What's your voltage at the battery with the car off, and what's your voltage at the battery with the car running?

 

[Squeetard]

I bet you those asshats knocked a wire off somewhere. The volt meter lead comes off the starter, which is right by the oil filter.

 

[Mark R]

Could be a problem with a fuse or a connector not plugged in correctly.

If they disassembled stuff to change an oil seal, then they may have taken some wires off, which haven't gone back on properly, or a wire has been damaged or a fuse has blown.

If the alternator has been changed, then it needs careful examination and testing of the wiring and fuses.

 

[nerp]

Yes, diagnose before swapping parts in and out.