2003 Elantra Alternator Wiring Diagram

[Deftwun]

I just changed the alternator in my car. I measured the voltage across the battery with the car running before the change and it read 10.5V so that led me to change out the alternator.

That was yesterday. I drove it about 20 miles after changing it with no problems. Today I go to start it up and it runs for about 10 minutes and then the lights dim, all dash lights come on, the brake light flashes with the turn signal, it basically just tweaks out. Then It dies and wont start. Starter will click but wont turn over.

So I decided to ohm out the connections on the alternator to look for any open circuits. There are 2 connectors on the alternator. I decided to measure the resistance across the length of them to rule out a fuse. The one that bolts to the alternator is ground and measures ok between the chassis and the post on the alternator.

The other connector is a plug with 2 connections / wires. One is a red wire that looks like the Positive battery connection. That Ohms out ok to the battery post. The other is a blue wire with a pink stripe. I dont know where this terminates or even if there could possibly be a fuse somewhere between it. Does anybody know where this wire leads?

[Em-squared]

to the forum.

[jsinton]

Usually you check volts at the battery to determine the charging system status. You should get 13.5+ at the battery with motor running and 12.5+ with motor off. There is an alternator fuse in the fuse box... 120 amp methinks. You should pay attention to your negative battery cables, as they are bolted to the body and in a rust-belt state situation a common problem is your charging system will take a dump in an older car. Take off the negative cables that are bolted to the body and clean up the connections real good.