521 KA24DE alternator wiring

[haubstr]

Don't know if this is the right section but I thought I would try. My swap is almost done but I can't find anywhere what to do with the alternator wiring. In particular the wires from the 521 alternator T connector and the plug on the back of the KA alternator. This truck already had the internally regulated alternator. If there is a link and hopefully pics that would be great.

 

521 T connector - Yellow and white with black stripe

Ka plug - White and white with red stripe

 

I only ask because the last swap I did the battery always drained and I don't know if it was charging or not. My aftermarket gauge showed it was but ???

 

Thanks in advance

Haubstr

[datzenmike]

I had my KA alternator wired backwards (switched) for 3 years. It was only when I got a volt gauge that I saw it randomly charged. I compared the wiring harnesses and made a good guess but it was 50 / 50 and..... I was wrong. I'm saying if you get it wrong it won't hurt anything.

 

With the ignition ON but not running, plug the T connection into the back of the alternator. If the charge light does not come on it's probably backwards. Just switch the wires.

 

 

What was happening was the battery had to discharge to a lower point (maybe 10.5 volts) and the alternator would start charging the next time I started it. As it always started on the first turn I never noticed anything wrong for years. I never noticed the red light was not coming on, who would? It ran fine so I didn't question it.

[banzai510(hainz)]

If your 521 was a 72 it had auto choke and you need to disconnect it otherwise battery drain .if swapping to a IR alternator and adding the 2 wire jumpers 

[thisismatt]

If you are looking at the KA alternator harness plug straight on with the locking tab on top, then the left pin is your L (lamp) to dash lamp and the right pin is S (sense) to +12v.  So looking at the alternator receptacle,  the right pin is your L (lamp) to dash lamp and the left pin is S (sense) to +12v.

[datzenmike]

I found my original journal diagram with a big X through it saying to reverse the wires.

 

Your White with stripe wire is the charge lamp. The solid Yellow the sense wire.

[haubstr]

Perfect! I'm going out in a few to hook it up.

 

Thank You guys for the direction.

[haubstr]

I ordered a new connector from Wiring Specialties but I got it and it was disassembled and had no wire with it. What size wire should I use 12 14 or 16 gauge?  

[thisismatt]

12 is probably excessive, 14 or 16 should be fine