Scottie-GNZ Posted May 30, 2000 Share Posted May 30, 2000 I am having the darndest time trying to figure this out and am about to hurt this car. I have an 87 vintage alernator with the single brown wire to excite the alternator. The original white/red wire is connected to the BATT terminal of the alternator. Prior to today the brown wire was connected off the ignition circuit. I get 13.7+V at the alternator but the battery is not charging and has drained down several times and this is the 2nd Die-Hard since this started. When the battery was fully charged it checked out OK. Up to the point of the white/red wire coming through the firewall, it checks out at 13.68+V but then everything after that is 12.6 or less, including the fuse box, cluster switches, solenoid and starter. This evening I trickled charged the battery up to 12.68 and had 13.71 at the alternator. Drove for 30 mins and had 12.33 at the battery. Spent the next hour with the car off and on trying to trace problem. Decided to get bold (desperate?) and run wire from alternator directly to the fuse box. Temporarily connected alligator clip and went to crank it and it was stone dead. Fired up with a jump start but I go discouraged and called it a night. Can someone PLEASE explain to me how the circuit flows from the alternator to the battery. Somewhere after the white/red wire enters the car I am losing voltage. I need to know where I could possibly be losing voltage. I have a Clymer but I am beginning not to trust it. E.g., in the harness I can see the white/red wire covered in black plastic but there is also a fat white wire in that cluster that is no where in the wiring diagram. I really need to fix this problem and I would love to run the car this weekend. TIA, Scottie Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 30, 2000 Share Posted May 30, 2000 Scottie, Have you ever considered a single wire setup? It basically has the exciter circut built into the alternator so all you need to do is run a wire from the bat terminal of the alternator to the battery and bypass the other crap. I would suggest this route since the wiring in your car is obviously showing its age and tracking down the problem will be similar to Mikelley's problem with his fuel. Save some hair on your head and overnight a new alternator from Summit. SpencZ MonsterZ Cont. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted May 30, 2000 Author Share Posted May 30, 2000 I do have the single-wire alt and that is exactly how I have it wired. My problem is that the white/red wire leaves the alternator with 13.7 but that voltage never gets to the battery. I looked at the GN wiring and they have a 10-guage wire directly from the alt to the battery terminal, so I plan on doing that today. After studying the 71Z wiring diagram for another 2 hours, I now see that the battery appears to get its connection from the alternator through the external voltage regulator, then the starter. I eliminated the external regulator and it is possible the wire from the regulator somehow was not reconnected. Slowly but surely I find myself wiring around the original 29-yr old harness. DEMONS, be gone from my Z-car Scottie Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted May 30, 2000 Share Posted May 30, 2000 I have my own wiring troubles, time is my current problem, I had considered a painless wiring kit, but for 500 bucks I don't know that its worth it. if worse comes to worse, I can always pull the harness in question and find one from a junk yard to replace it or rewire it myself using the datsun connectors. I wish I had a better schematic than the one in the haynes manual. For the 77 280Z its pretty small and it didn't come out to well in my copy of the manual. Maybe I need to hunt down a datsun shop manual and see what I can find. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted May 30, 2000 Author Share Posted May 30, 2000 Problem Solved!!! Now time will tell. I looked at the GN wiring and saw it had a wire directly from the alternator to the battery and wired it up that way. I can only imagine that the big white wire that goes to starter is not connected to anything. Locutus, I feel your pain when I look at the wiring schematic for a late 280Z. Considering I dont have a/c, radio or any amenities, that painless wiring kit is beginning to look good. The factory fuse box is a disaster and I have bypassed it twice. Scottie Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 30, 2000 Share Posted May 30, 2000 I'm throwing away the whole harness and starting over. I will keep the few datsun connectors that go to the steering column but the rest is going byebye. I am going to buy the painless wiring 12 circuit universal block and run my own wiring. It won't be easy...but there is no way I'm going to rely on the stock wiring (which was bad to begin with in 1973) in my baby. SpencZ Monsterz Cont. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.