Wiring hell--a question

[jhm]

I've run starters and alternators from these guys, and have been extremely happy with the quality, price and customer service:

https://www.dbelectrical.com/

[Fridge Gnome]

I used an 140A alternator from a cadillac deville. Needed a little modification of the alternator mounting points, but not too bad. Holes are in the same spots, but the mount is too thick iirc.

 

Autoparts stores sometimes have them in stock too.

 

edit sorry, I'm thinking l28 alternator mounting points, not sure if they are the same.

Edited June 25, 2020 by Fridge Gnome

[wingwalker]

I have made a bunch of progress and have the car running (and what a lovely sound that aggressive cam gives the engine as its exhaust blasts through a Flowmaster). Wiring is my weak area, so I was pleased with the following:

1. Started on first crank

2. Did not smoke anywhere

3. Did not blow any of the big fuses replacing the fusible links

4. And I was thrilled to see all the gauges actually working (I didn't try the lighting for them or the lights on the car).

 

However, the tach doesn't work. Nada. I tried to follow the book as it pertains to HEI, but as I've written before, the wiring on this car had been butchered. This means I very well may have grabbed the wrong blue wire or the wrong black/white wire (or both). So I want to bypass the existing wiring and go directly from the HEI to the tach. And I know I need a 15k ohm 1/2 watt resister in there somewhere. Can someone please supply me with a simple schematic, maybe suggesting where I can pick up switched power as needed?

Thanks

P.S. I'm finishing the body work (block sanding in 100+ degree heat) and now trying to line up an affordable painter. The interior is all restored and ready to be installed after the paint--so the end is in sight. Whew. I started this in 2017--a long, hard process. But fun.

[jhm]

You are correct in that JTR (and others) recommend a 15K ohm resistor in the blue line between the original ignition box to the tach (and I have done that on some previous swaps with acceptable results).

 

HOWEVER.....IIRC, in my last SBC swap I just ran the line directly from the HEI to the tach (original gauge) and it worked fine...no additional resistance needed in the feed wire.  I did have to calibrate the tach, using the small calibration screw on the back of the gauge.  No bouncing needle, reads accurately and easy-peasey.  This was on an early-version 260.

 

Hope this helps.

[wingwalker]

JHM. that does help. Now I just need to know where to hook up what. On the HEI there is a tach terminal, so I'm assuming a wire directly to the tach from that? Does it need to be switched or any other deviation from a straight line? Forgive me, I know little about wiring (even after wiring two cars--but then I always had my dad to advise me ... but he's gone). Is that one wire all that is needed (in addition to lighting), or is there a source of power involved?

 

And if anyone wants to draw up a schematic, I'd be forever grateful--or at least grateful for a very long time.

[wingwalker]

Fridge Gnome, I should respond to your post of last year. Urged on by you, I bought a 140-amp alternator. Then I went to a chart that told me I was way short on capacity of the alternator wire. And as mentioned, my alternator is on the wrong side (air conditioning considerations drove this). So this distance required far heavier gauge wire to the alternator. More wiring hell. Nothing is simple when you start making changes to these old cars (hot rodding, we called it back in my day ... and yes, I'm a geezer in his 80th year). At any rate, I was pleased to see the generator was charging properly after I started the car.

 

By the way, one of the reasons for the extended length of this project is that I spent a great deal of time finishing a book on my exploits (and shootdown) as a Navy pilot during the Vietnam Air War. That book is finally out in hardback, paperback, e-book and recently as an audiobook. Reviews have been very favorable on both Amazon and Goodreads. It is titled Return to Saigon, and it is available through bookstores, Amazon and other outlets. Check it out. Like the 280Z V8, it's a project I'm proud of.

 

I'll solve the the tach issue, then it's off to the body shop for paint. But, whoa, have you checked the prices for paint lately? Around here, all the shops are super busy with insurance work, so they are quoting prices ranging from $6,500 ("if it doesn't need any body work") to $10K. Yikes! 

[rossman]

Very cool wingwalker!  I have to check out your book.  Thank you for your service! As a kid brought up on Looney Tunes, every time I see Walla Walla WA, I think of the Little Giant Vacuum Cleaner Co. 😆

 

 

[wingwalker]

Yep, Rossman, it's a jokey name for what turns out to be a very cool town. We moved here in 2004 from California (and Mexico before that), where we had lived and cruised aboard a sailboat for two and a half years.

 

In the mid-1970s two hobby wine-makers discovered that grapes grown on what formerly had been Walla Walla wheat land (and later on rocky hillsides) produced wonderful wine grapes. Now there are some 120 world-class wineries here. One recently had a red judged best in the world (in London judging). So, this has become the Napa of the Northwest, and with this has come fine restaurants and lodging.

 

I ran a wire from the "tach" post on the HEI directly to the tachometer feed, and nada. Dead. Then I noticed that the needle is stuck at about the 800rpm spot. It should fall to zero, so I think the that gauge itself is toast. I'm going to move on. I don't need that input to drive, and I do want the car painted and the interior finished so I can use it this summer and fall. Later I'll likely replace the dead tach with a Speedhut gauge. Maybe the rest of the instruments at the same time.

 

Thanks for checking out the book. I'm rather proud of it, since it has garnered some great reviews. And, along with some of the guys mentioned in the book, I've been invited to sit on a panel at the annual Tailhook Reunion in Reno in September. Theme of the reunion this year is the Vietnam Air War. I got in 137 combat missions, but the other pilots on the panel were all over 200 (and they managed to not get shot down). I have already purchased plane tickets for my wife and me, but I'm thinking it would be great fun to drive the Z down to Nevada from here--it's about a 10-hour run. I'll need to hustle to get her painted and finish the interior by then.