Jump to content


Photo
- - - - -

'77 620 Alternator wire colors help needed


  • Please log in to reply
5 replies to this topic

#1 stevensonDNL

stevensonDNL

    Senior Member

  • Members
  • PipPipPip
  • 152 posts
  • Location:Everett, WA USA
  • Cars:02 Corolla LE, 93 Corolla DX Wagon, 98 Tacoma, 65 Pontiac Catalina 2 + 2, 77 Datsun 620 KC pickup

Posted 28 July 2009 - 01:29 PM

Thank you to ggzilla for your post last May that helped me determine that my alternator is good. I'll be checking my external voltage regulator next.

I need to make sure I'm connecting the wires correctly to the "F" and "N" terminals of my Hitachi alternator. My problem is that the "Tee" connector that goes to those terminals is completely gone. I have two female crimp spade terminals to connect to the alternator. Does the yellow wire go to "N" and the white/ black wire go to "F"? I see conflicting information in my Haynes repair manual. Can somebody take a look at their truck for me?

I've included the illustration from the Nissan factory manual that ggzilla used:

Posted Image

Thanks,
Dan

#2 nukeday

nukeday

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 913 posts
  • Location:Willamette Valley, OR
  • Cars:...

Posted 29 July 2009 - 09:09 AM

This might be helpful, looks like you've got it analyzed correctly per the factory drawing:

http://www.olddatsun...dat620-1977.pdf

If you've not visited the site, there is a lot of really useful stuff there:

http://www.olddatsuns.com/index.htm (the620.com)

toil and learn or have deep pockets.

"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

"Well done is better than well said." - Benjamin Franklin

#3 stevensonDNL

stevensonDNL

    Senior Member

  • Members
  • PipPipPip
  • 152 posts
  • Location:Everett, WA USA
  • Cars:02 Corolla LE, 93 Corolla DX Wagon, 98 Tacoma, 65 Pontiac Catalina 2 + 2, 77 Datsun 620 KC pickup

Posted 29 July 2009 - 02:37 PM

Thanks for responding, nukeday. yeah, that is an excellent site packed full of valuable info that's helped me alot already. I'm certain my problem is a bad voltage regulator. There should be a +12VDC output from the "F" terminal of the regulator (white/black wire) going to the alternator "F" terminal, which allows the alt. to charge the battery, but the voltage isn't there. I ground off two case cover rivets to peak inside the regulator, and found it's a solid state type. I pretty certain it's bad. I just bought one on ebay a few minutes ago.

Dan

#4 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 44,627 posts
  • Location:Vancouver Island
  • Cars:'78 620, '74 710 sedan, '76 710 goon

Posted 29 July 2009 - 02:46 PM

I think the F has a White/Black stripe and the N has a Yellow wire on the '77.

#5 stevensonDNL

stevensonDNL

    Senior Member

  • Members
  • PipPipPip
  • 152 posts
  • Location:Everett, WA USA
  • Cars:02 Corolla LE, 93 Corolla DX Wagon, 98 Tacoma, 65 Pontiac Catalina 2 + 2, 77 Datsun 620 KC pickup

Posted 30 July 2009 - 04:26 PM

Thanks datzenmike, I now know your right after I pulled the voltage regulator and found the same wire colors at the VR's connector. I've got a new VR coming via ebay now.

Dan

#6 stevensonDNL

stevensonDNL

    Senior Member

  • Members
  • PipPipPip
  • 152 posts
  • Location:Everett, WA USA
  • Cars:02 Corolla LE, 93 Corolla DX Wagon, 98 Tacoma, 65 Pontiac Catalina 2 + 2, 77 Datsun 620 KC pickup

Posted 06 August 2009 - 10:07 AM

I'd like to share something to check for when troubleshooting alternator/ external voltage regulator problems. I was at a loss to understand why, on my "77 620, even with a new solid state electronic VR just installed, that I still wasn't getting the alternator to charge the battery. After describing the problem to an auto mech. friend, he reminded me that the VR needs +12V to it's "IG" terminal (white/blue stripe wire) so the VR knows to turn off the cutout to the alternator "F" terminal when the engine is running. The cutout needs to be off with engine off to prevent the battery from discharging through the alternator field winding. Anyway, with engine off and ignition switch "on", I had no 12V at the VR engine harness connector. I traced the problem back to the upper lefthand fuse in the fuseblock under the dash. The fuse was good, but one of the fuseholder clips was intermittent, which I discovered by accident with the voltmeter probe tip. If I pushed on the clip just right, I'd get the 12 V at the VR. After reconnecting the VR and starting the engine, my alternator was charging the battery again. The fuse clip is riveted through the fuse block to a copper bussbar on the rear of the block that has 12 V applied when the ignition switch is on. I guess that the rivet is just loose enough to create the intermittent condition.

Dan