GM Alternator Woes

[HuD 91gt]

I am attempting to upgrade my '71 externally regulated alternator to a CS144 alternator.

 

Ive used the MSA converter plug which rearranges the appropriate wires, and includes the diode required.

I connected the 12v constant wire (yellow on T plug) to the S "sense" wire on the 4 prong alternator output. I connected the other wire from the T plug "switched" to the F "field" plug.

I start the car and I am not getting any charge. It's sitting at ~12.5volts.

All the documentation out there talks about 280z, these have I believe a discharge lamp.  This is considered an excited correct? Does a 240z require some sort of resistor in it's place to "jump start" the alternator?

FYI, I've decided to upgrade as I am installing megasquirt, and I figure and upgrade would be required.

 

 

 

[SteveJ]

Whose write up did you use?

This one pretty much describes the swap I did for a friend: http://forums.hybridz.org/topic/49864-94-amp-ac-delco-alternator-swap-details/

[Zed Head]

Did you measure voltage at the two T plug wires to be sure it's there?  Key On.  And where did you get the diagram for the CS144 plug?  If you're only using two, maybe F is the wrong one on your CS144.

[Zed Head]

Just found this on the old interweb.  #35.  "F" is probably for monitoring alternator condition.  You need to use "L".  I'd guess.

http://67-72chevytrucks.com/vboard/showthread.php?t=528474&page=2

[HuD 91gt]

Wow, thanks for the quick reply. I wasn't able to use any writeup actually as I have an alternator from a heated windshield car which has 4 prongs as apposed to 3 in all the writeups. The 4 wire alternator has the 4 that zed head posted.

 

If I connect the switch the F for the L, will I require a resistor? I was reading so many sources, I confused myself. Surprised that diagram never showed up in my searches as I was looking for exactly that.

[Zed Head]

The bulb in the L wire on your car is a resistor.  I have read though that the CS alternators don't like too much current on the L wire.  I'll see if I can dig up the reference.

I searched "cs144 pin out" and looked at images.

[Zed Head]

Here's that reference.  It's not very good, since it's really referencing voltage drop.  Actually it doesn't make much sense.  It's for the CS130, which is what Steve linked you to.  If that application worked, yours probably will be fine.

http://www.hotrodlane.cc/ONLINETECH/CS130DREG.html

[HuD 91gt]

Thanks Zed. I didn't actually think the 240z had a light, that's why I'm wondering about the resistor. Maybe it does and I'm just out to lunch? That first link you sent made me worried is it says without a resistor can damage the alternator.

[Zed Head]

I forgot about that.  It's funny though, the wiring diagram shows a bulb in the circuit, before the regulator.  Excerpt below from 1973.

One of the pre-voltmeter people would know more.  

[Zed Head]

And the link that Steve showed is for 280Z's.  Better be careful.

[Zed Head]

Looks like L comes through the ammeter shunt.  Probably some resistance there.  Where's the electrical guys?  I'll step away.........

Edit - I think the above is wrong.  The 260Z diagram is hard to trace, all black and white.

Edited October 22, 2016 by Zed Head

[HuD 91gt]

No, thanks zed head. Really appreciate your input. The '71 manual is the one which is missing in the library so I'm weary of believing the newer model diagram. All I know is I don't have a light (it's in the console correct).  Hopefully someone can answer this as it's really tempting to just swap prongs, and start it up.