So, a little background. For my AC system control relay, I need a signal that ties into the charging circuit (D+61). On a Volvo, this would travel to the ground side of the idiot light, and ground through the alternator (D+61 terminal) when the engine is not running. 

 

As far as I can tell, there is no way to wire this to the alternator, as it doesn't have a equivalent connection

75 280Z

 

Volvo alternator, has an additional diode pack. I don't even know if using a later internally regulated Datsun alternator would fit the bill.

 

I read in another thread (can't quote it here) @SteveJ - That the L terminal of the V reg would serve to provide the charge indicator lamp circuit I need

The 1975 wiring diagram shows a wire connected to the L terminal, but it also shows a voltmeter, so I'm assuming that is an error

 

77 color diagram shows the wiring through to the voltmeter & charge indicator lamp

 

75 diagram - The wiring diagrams I have show a Blue or a Grey connected to the harness side of this. Following it through, it seems to go to the Interlock Relay (which my car doesn't have)

   

FSM shows a W/R wire connected to the L terminal though. 

 

 

 

So, to get to the point, does the '75 voltage regulator in fact have that L terminal & internal circuit that I could utilize? 

 

 

Edited September 29, 20231 yr by HusseinHolland

Here is the deal. As far as I'm concerned, there are gaps between the documentation and reality for the 75. On page EE-14, the manual shows a charge light. Since I've never owned or really worked on a 75, I can't tell if it exists. The 75 should still have an ammeter as far as I know. I don't have a full 75 FSM, so I don't have the BE section to cross-check anything. The parts manual shows an ammeter for the 75. So where would the charge light be? I don't know.

Thanks Steve - I have the 75 FSM (original hardcopy). It matches the online copy that I have, besides the glitches from scanning

There is no charge lamp on my 4/75 280Z. I do have the ammeter . Manual shows an interlock relay, but I don't have that either.

 

EDIT - when the rain stops, hopefully Sunday - I'll look at the actual harness plug & see if I can wire a test lamp to the L circuit. Should be easy enough to determine from there if it will suit my needs. Thank you for pointing out the L terminal in the other thread.

 

from page EE-14:

 

EDIT  -lookng through my earlier pics - I have an empty spot in the v/reg harness for the L terminal 

EDIT - thinking about the actual lamp - I can repurpose the non-functional low fuel indicator. I'll cut the Bl/Y wire back in the harness & connect that to the L terminal & Blk/Wh wire at my AC relay.

I've taken a Volvo seat belt warning lamp & sanded off the symbol, so I can fit that in the console for the charge indicator lamp

 

 

Edited September 30, 20231 yr by HusseinHolland

wired my relay feed to the L terminal via a new charge indicator bulb. Circuit works exactly as @SteveJ described. 

repurposed rear defogger lamp for charge indicator

Bulb holder w/spade terminals

Edited October 6, 20231 yr by HusseinHolland

fitted Charge Lamp