Flauski Posted February 16, 2023 Share Posted February 16, 2023 Have a 1977 Nissan Laurel KHC230 and the wiring has me a bit stumped. I know there are some OS experts in this field. I don't want my car to catch on fire / melt wires but I don't want to have to disconnect the battery every time it is off too! Must be some of the last cars to have external regulators. I have replaced my alternator with an IR one. I have tried following Nissan / Datsun instructions online which are a little conflicting but the wiring colours seem to match. It all seems to depend on whether other relays are in the same circuit. 1. Alternator S (signal) (Y) 2. 12v from fusable link (W) 3. 12v acc? (WR) 4. Ground (not needed) (B) 5. Alternator L (lamp) (WB) 6. +12v but shares same colour wire to a lot of other relays etc? (WL) This is what I used; After following those above instructions I can confirm - Alternator appears to be working / charging, however there are some issues - 1. warning lamp for charging stays on 2. There is draw on the battery when the car is off, relay(s) can be heard click on when positive connected. It appears that the ignition accessory relay / intermittent wiper box are powered up. Will I fix it by following these instructions instead? This shows 5 white with black stripe + 3 white with red stripe connected instead of 5 + 6 connected. Out of shot of the wiring diagram for my car it would appear that the white/red (WR) ends at the actual charge lamp on the dash? Wiring diagram for my car; Any ideas? Is changing the wiring as indicated going to stop power being fed to other devices when car is off? Or am I going to have to do something more drastic with regard to sourcing power from somewhere else? Quote Link to comment Share on other sites More sharing options...
kicker Posted February 16, 2023 Share Posted February 16, 2023 I did the same conversion on my 260C, I'll see if I can dig up the details but from memory for me it was as simple as connecting two pins on the plug directly and connecting another two with a diode. Quote Link to comment Share on other sites More sharing options...
fletch Posted February 16, 2023 Share Posted February 16, 2023 I did it a while ago and just wired the charge light (WR) to the L terminal of the alternator and the S terminal to the battery. What alternator have you got? Quote Link to comment Share on other sites More sharing options...
Flauski Posted February 16, 2023 Author Share Posted February 16, 2023 13 minutes ago, kicker said: I did the same conversion on my 260C, I'll see if I can dig up the details but from memory for me it was as simple as connecting two pins on the plug directly and connecting another two with a diode. Yep that's what I've done, per the first pic of two plugs inc a diode. The issue is around the extra relays etc in the same circuit. For late model Z it is a seat belt warning / fuel pump, for me it appears to be ignition accessories and auto choke. I know changing the wires linked by diode may solve the lamp issue but potentially not the rest (triggering relays when car off causing draw on battery.) 1 Quote Link to comment Share on other sites More sharing options...
kicker Posted February 16, 2023 Share Posted February 16, 2023 Gotcha, didn't see the rest of your post sorry. My plug looked as below which I think is the same as what you are thinking of doing. 1 Quote Link to comment Share on other sites More sharing options...
Flauski Posted February 16, 2023 Author Share Posted February 16, 2023 Have now tried swapping to same as you @kicker, connecting 5 - WB to 3 - WR and diode facing the same way - it has made no difference. Still charging, charge lamp stays on, loud click from relays heard when car is off and battery connected. The alternator is a Mitsubishi AQ2250? 50 or 60A IC. Can see from the pic I just took that it is wired correctly to S and L. Quote Link to comment Share on other sites More sharing options...
grant76 Posted February 16, 2023 Share Posted February 16, 2023 if wiring is correct is internal regulator not working so charge light stays on?? Quote Link to comment Share on other sites More sharing options...
Flauski Posted February 17, 2023 Author Share Posted February 17, 2023 Not sure? I suppose I could try another alternator but it came off a running car. Won't solve the problem with draw when car off anyway. Quote Link to comment Share on other sites More sharing options...
fletch Posted February 17, 2023 Share Posted February 17, 2023 22 hours ago, Flauski said: Have now tried swapping to same as you @kicker, connecting 5 - WB to 3 - WR and diode facing the same way - it has made no difference. Still charging, charge lamp stays on, loud click from relays heard when car is off and battery connected. The alternator is a Mitsubishi AQ2250? 50 or 60A IC. Can see from the pic I just took that it is wired correctly to S and L. I think the S wire is sending volts back to the ign circuit the way you are trying to connect it. Can you try looping the charge light to the L and temporary hook the S off the alternator straight to the positive terminal of the battery. It's just a reference signal from the ign circuit so the alternator can up the volts if there's a big load and the ign circuit volts are dropping. Quote Link to comment Share on other sites More sharing options...
Flauski Posted February 18, 2023 Author Share Posted February 18, 2023 Did that today ^ Light stays on but no solid click of relays engaging when connecting battery with key off. Some things are not getting powered, I know the auto choke relay is one for sure. Had to google the factory part number to work out what it was and as you can see, it does not exist on the wiring diagram?! Quote Link to comment Share on other sites More sharing options...
fletch Posted February 18, 2023 Share Posted February 18, 2023 Bugger. See this link for a good explanation of how the original reg works https://240z.life/voltage-regulators/ also i think this covers it, even tho its slightly different. Also mentions auto choke relay near the bottom of the page. The 510 diagram you posted looks like it suits your wiring, but the pins in the plug are different to Kickers photo. You must have the Yellow wire in your regulator plug splitting off to the choke relay coil and its not shown on your diagram. You could do some probing with a 12v wire onto each pin of the regulator plug (car side) and listen for the clicks of the relay to confirm what feeds it. Just don't touch it on the ground pin. Im surprised the light is staying on when you connected it directly to the alt and the S to the battery. Have you got a voltmeter? Did the voltage rise once the engine was running? I once did a rush job engine conversion on a 90s nissan. I had the S wire connected but i hadn't run the charge light wire to the dash. Temporarily i had to start the engine, then touch a wire from battery positive to the L terminal to energize the field and get the alternator to charge. Once it started charging it was away. If your charge light is staying on, there might be a problem with the alternator? Quote Link to comment Share on other sites More sharing options...
Flauski Posted February 22, 2023 Author Share Posted February 22, 2023 On 18/02/2023 at 23:23, fletch said: Bugger. See this link for a good explanation of how the original reg works https://240z.life/voltage-regulators/ also i think this covers it, even tho its slightly different. Also mentions auto choke relay near the bottom of the page. The 510 diagram you posted looks like it suits your wiring, but the pins in the plug are different to Kickers photo. You must have the Yellow wire in your regulator plug splitting off to the choke relay coil and its not shown on your diagram. You could do some probing with a 12v wire onto each pin of the regulator plug (car side) and listen for the clicks of the relay to confirm what feeds it. Just don't touch it on the ground pin. Im surprised the light is staying on when you connected it directly to the alt and the S to the battery. Have you got a voltmeter? Did the voltage rise once the engine was running? I once did a rush job engine conversion on a 90s nissan. I had the S wire connected but i hadn't run the charge light wire to the dash. Temporarily i had to start the engine, then touch a wire from battery positive to the L terminal to energize the field and get the alternator to charge. Once it started charging it was away. If your charge light is staying on, there might be a problem with the alternator? Yes, the screenshot above of a factory manual is indeed the factory manual I drew colours on to highlight. Yes, the auto choke relay is not even shown but can confirm it directly feeds off the yellow wire going into regulator. The voltage raises to an acceptable level (about 14.5v) when car is started so alt must be working. Still can't work out why dash light it on, every thing I have read suggests if light is on, alt is not working and won't be charging. Quote Link to comment Share on other sites More sharing options...
Flauski Posted January 30 Author Share Posted January 30 So the 'electric choke relay' per the above image doesn't appear to function. Am I correct in that on a standard relay white/blue is 30 and blue is 87? Why would the relay itself buzz like crazy? Quote Link to comment Share on other sites More sharing options...
fletch Posted January 30 Share Posted January 30 Yes 30 and 87 Have you got it wired up as per the pic? Maybe move the yellow wire to ign. The relay hasn't got any trickery in it where it auto cuts out as it warms up. Maybe your yellow wire which is now sense if you have jumped it as per above, hasn't got a great connection to 12v. Plus it will always be on as its connected to battery and ground. Quote Link to comment Share on other sites More sharing options...
Flauski Posted January 30 Author Share Posted January 30 7 hours ago, fletch said: Yes 30 and 87 Have you got it wired up as per the pic? Maybe move the yellow wire to ign. The relay hasn't got any trickery in it where it auto cuts out as it warms up. Maybe your yellow wire which is now sense if you have jumped it as per above, hasn't got a great connection to 12v. Plus it will always be on as its connected to battery and ground. Isn't the white/blue ignition? Are you saying tap off that for the relay power as well? Yellow wire gives the 12V only while engine is running right? white/blue is ignition and will power relay but also provide the source to auto choke when ignition is on? I will check the voltage at the yellow wire. Quote Link to comment Share on other sites More sharing options...
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