Wiring alternator for tach drive

[PToombs]

I had to add a W-wire for my tach to work,here are basic instructions and some pictures.

First-remove alternator,and remove backcover, 3 small nuts, and 1 large nut which holds plastic wire guard. May have to pry gently.

 

[PToombs]

Second-Then remove screw from stator wire. I made short jumper wire with an eye on one end and a spade connecter for easy removal. Double heat shrink on eye end for protection. Install on stator screw.

 

[PToombs]

Third-Carefully trim back cover for wire passage. Install back cover,feeding wire thru cover. Install nuts and install alternator,wires, etc.

 

[PToombs]

Forth-Wire the rest to the tach, if you did it right it will look like this!

Good luck 1st genners!

PS-Obviously I gotta put the dash back!

 

[swankmetal]

ya pete!!! looks like even somebody as poorly wired as me can do it! i think we all know what i'll be doing this afternoon. so pete, did you get the one that runs off the alt, or the one i got(that's supposed to run off a sender)? anyway, thanks a million!



dave

 

[PToombs]

Holy cow, I just sent you a pm, you must be hungry for this thing. I got the same one you did, but w/ the black bezel. Tomorrow I'll try to bring home the photo tach to see how accurate it is. As you can see, I still gotta figure out where to put it, it won't fit in the dash on either side.

 

[CLiberty]

What brand/model of tach are you working with?

 

[swankmetal]

ya pete. i was hungry for that one. it was done less than an hour later. a whole lot easier than i was expecting. many thanks for doing the homework on this one. i'm sure many will benefit. can't wait to hear how accurate it is. i spent a while trying to figure out where to put it too. haven't come up with anything yet. thinking about making a dash top "pod" though. prolly go most of the way across, but have room for all the gauges i'll ever want. one of my buddies has a cnc plasma cutter, and another runs a cnc machine shop. between the three of us, i think we'll be able to come up with something. and be able to make more than one(hint,hint).



dave

 

[JLEONARD]

I went this way with an Isspro tach a few years ago. It required a little tweaking with an optical tach to dial it in.

It was accurate initially, but lately has been giving me fits. . I think it's temperature related so it needs to go back to Isspro. (cold days seem to drive it crazy)

Jay

 

[bgilbert]

I think me and Jay have the same Isspro alt tachs. Big one 3 3/8". Has its own base to bolt to the dash. No troubles from mine, knock on wood.

 

[JLEONARD]

Looks the same but I have a white needle. Mine's mounted in a gage cup and tiewrapped to the column. I think there's a pic in my reader's rig album.

 

[PToombs]

Hey Bill, next time can you take a better picture? I can't see what R's your turning! :-laf I didn't want to drill holes in my dash top. Thinking of a gauge cup and bolting in the courtesy lite hole. Jegs has one for 22. 99, part #105-5204, but stainless or aluminum is nice(hint,hint). I hate to pay more for the cup than I payed for the tach.

CLiberty-check the thread "electrical problems" for the link or ask swank,he be the man with resources.

 

[swankmetal]

oh yeah. this one.

 

[PToombs]

I'm cumpoter illitorit,but larnnin. I still gotta learn how to do links. One step at a time!

 

[swankmetal]

turned out pretty good for me too, btw. here's a pic. have you had a chance to check it for accuracy, pete?

 

[PToombs]

Looks good Dave. What did you do have a practice alt. there? And yeah, I did check it tonite, I was shocked! :--) At 1000 rpm, actual was 1020, at 2000 rpm, actual was 2050, at 3000 rpm, actual was 3090. Give or take 5-7 rpm. Dip switch set on 2:1. I thought it was off about 200. What really pi$$ed me off was when I turned up the pump, I know I was turning 3300 at WOT, now its only 3125. :{ After I fix that little attitude problem then fuel screw locking collar amputation and timing adjustment. a trip to the dyno and good to go!

 

[swankmetal]

well, got 'er runnin tonight. runs great! only one problem. unless the brakes or lights (the only two things i've tried) are on, the needle jumps between 550 and 650. when the brake pedal is pressed or i pull the light switch, it rides rock steady at 800. wth????? is this as simple as a bad ground or something? lemme know what you think if you would. and thanks again. seeing that thing come to life put nice big smile on my face.



dave

 

[PToombs]

Dave, I hooked up all my wires to the factory tach harness, then cut the signal wire and hooked the W wire to that. Mine idles at about 800 also, but steady. Try turning on other elec. stuff of different loads,radio,fan etc. Maybe changing the draw is affecting it some how?Or could be ground.

 

[BushWakr - RIP]

Ok... . I really suck at electrical stuff but... . it does sound like a poor ground somewere. Usually that is what causes the unstable symptoms you describe... . now, it could be a ground like the one on the neg terminal on the battery that runs to the rad support, or, another that is breaking down when you increase load (like turning on an accessory or using the breaks etc).

Have you had any fuses pop??? Maybe try loading the system as much as possible and seeing if it will trigger a fuse... that will lead you in the right direction... ... did I mention I really suck at electrical stuff.....



HEY GUYS>>> Electrical stuff here..... belly up to the fuse panel... eh !



pb...

 

[JLEONARD]

The majority of the time a bad ground is the cause for things like that.

My alt tach stays steady with any electrical load. Not always accurate anymore as I said, but always steady.

Jay