It's also run through a parallel circuit of a 470 ohm resistor and the bulb. If the bulb is open, the current through the resistor is still enough to turn on the voltage regulator (assuming no other open circuit, that is).

 

Thanks. I plan to check power at that fuse. What do you mean about the current limiter? Isn't that within the voltage regulator on the alt?

 

New update.. There was no fuse in F19.... but there is 11.5v when the key is on at the terminals where the fuse should be. Unfortunately the connections for the fuse are super loose... it may be that the fuse fell out and the previous owner didn't even realize. Is there any way to snug up the fuse connections?

 

Well, that explains the lack of charging.

Dental pick or similar. You might be able to tighten up the fingers to hold the fuse. Ootherwise, you'll need to splice an external fuse holder into the circuit.

 

You need to make sure that the fuse has a clean and snug connection. Anytime an electrical circuit has a loose connection it will cause heating at the joint and that heating can be bad enough to burn up the fuse holder, lamp socket, wiring or what ever else it happens to be part of, or even start a fire there. In houses, loose wiring joints is one of the leading causes of house fires.

 

Yeah, I couldn't see a good way to get a pick in there. I purchased a used fuse box on ebay for $40... Seller "guaranteed" that all the connections were tight... so I guess we'll see this weekend when it comes in.

 

Good luck with it. Hope you don't swap this problem for a different one.

 

Final update. After installing a new fuse box due to loose fuse 19, everything works fine, alternator now charges battery and beeping for airbag sensor went away. Thanks to everyone for all the suggestions and help!!