2 problems.
one, I picked up a 4 wire heated O2 sensor for a 4th gen, and they changed the wire colors on me. This one has a grey wire (terminal A) , black (B) and two white wires (C+D). Which is which?

two, the brand new no name one wire altrernator doesn't seem to be doing it's job. I only show 12 volts with the car running. It didn't come with instructions, so I assumed that the wire went to the battery junction on the solenoid. Am I missing something? some reason it's only showing 12 volts with No accesories running?

 

Jester,

I reverse order:

The one wire alternators should have on large (AWG 8 or larger) should be connected to the battery, unswitched. Does the alternator have the "D" shaped test hole in the rear half of the housing? You can do a maximum output test if it's there.


The pinout I have for a 4-wire sensor is as follows:



I'm guessing the two white wires are for the heater element. If you "read" the connector across the terminals (A, B, C, & D) you should be able to identify the connections. You should also be able to verify the heater element leads with an ohmmeter, and the signal ground lead should also be a case ground (ohmmeter again). That should leave only one wire as the signal lead.

 

Guess I'll just have to go buy batteried for my DMM then. The way mine is, from the top down on that diagram, is grey black white white. why the signal wire and the element hot wire should be the same color is beyond me.

 

Jester,

If you ground the test tab recessed in the "D" shaped hole briefly, it will saturate the rotor (field) windings and force the alternator to maximum output. I wouldn't do this any longer than is necesary to get a voltage reading, though. It's common to set an error code when this is done (System Overvoltage) but the components can take it briefly. Just turn off all the accessories, radio, amps, etc.

 

Ahh cool man, I'll try that. thanks.