What guage wire to use for TACH lead on dizzy?

[TIMSPEED]

Currently, I have prolly 20 or 22 guage copper wire (the solid piece, not the multistrand like regular wire), is this a bad thing? Should I change all my tach wires to multistrand silver wire, as well as up it to 14 or 16 guage? I think this is what's causing my tach to bounce around at idle, in tune with the headlight flicker.

[Russell]

Still say it sounds like your alternator isn't producing enough juice for everything at 600 rpm...

Can you maybe build some sort of chipboard that'll take in the varying voltage and convert it to a steady 12 volts?

[TIMSPEED]

Originally Posted by Russell

Still say it sounds like your alternator isn't producing enough juice for everything at 600 rpm...

It SHOULD though. It just started doing this since the new motors been put in. So I'm thinking somewhere there's either a short, or the alternator I got SUCKS.

[1972C10]

Idle it up to 800-1000 I bethca it stops all that.

[bigblock73]

I run 16 ga wiring for my tach, and most of my Painless wiring kit is 16 ga as well.

['85Silverado]

I used to have a tach bounce like that at idle, but it was an old tach that required a filter for use with HEI. Does the engine miss when the tach bounces like that?

[Grim Reaper]

My tach bounced at idle it was a bad plug wire.
Soild core wire has no place on a car. 16 gage would be plenty for a tach. A 22 gage fine stand wire will carry a cleaner signal then a 22gage solid. Electricity travels on the outhside of a wire not the inside. The stranded will have more surface area. Its the same reason our brains look like coliflower. more surface area.

[TIMSPEED]

Originally Posted by '85Silverado

Does the engine miss when the tach bounces like that?

Nope, I know for a fact that my idle is perfectly smooth at 650rpm, but whenever I turn my headlights on, the lights flicker and the tach needle bounces between 900-1000rpm...turn the lights off, presto back to perfect 650. I'll change all my solid core wires to multistrand. I probably have more solid core wires than I should.

[86 Red_Bowtie]

Need bigger alternator

[76HighSierra]

I really don't think that running a bigger alternator is going to help. Alternators that are wound to run higher amps, usually run MUCH lower amps at idle than a stock alt. If anything, have the amperage output of your stock alt. tested to see if it falls into spec. in accordance with it's rating. I would tend to think his alt. isn't even the problem, but try the same "test" you stated, making sure that all other sources of current draw (stereo, A/C, etc.) are OFF. If turning some of the aforementioned items ON creates a difference in the tach, then have the alt. tested. What kind of tach are you running? Is it an "el cheapo"?

[TIMSPEED]

Originally Posted by 76HighSierra

making sure that all other sources of current draw (stereo, A/C, etc.) are OFF. If turning some of the aforementioned items ON creates a difference in the tach, then have the alt. tested. What kind of tach are you running? Is it an "el cheapo"?

It's just when I turn on my headlights. This is my tach
Auto Meter Tach

[1972C10]

Ive got that same tach in my 3/4 ton Good qaulity tach ive never had a bit of problems. Mine puts out 14.5 volts at idle though.

Get a good voltmeter after it and see what yours is putting out.

[corn]

I was always told that an alternator doesnt charge below 750 RPM...corn

[TIMSPEED]

Originally Posted by cornfed63

I was always told that an alternator doesnt charge below 750 RPM...corn

My vette idles perfectly at 600-700rpm. No electric problems at all. Albeit TPI, but still...I DID have a charging issue, because I was running an underdrive pulley on the crank, but I fixed it (and I don't remember how!)
I changed the wires tonight, to 16-guage multistrand...looks better now..but still no different. Any lower than 700rpm idle and the lights flicker and tach is unhappy.

[1972C10]

Will it charge right at 800? I seriously idle any of mine with a cam around 1000 In neutral

[TIMSPEED]

Originally Posted by 1972C10

Will it charge right at 800? I seriously idle any of mine with a cam around 1000 In neutral

At 700rpm+ it'll charge perfectly fine. But I just think I'm wasting gas idling it that high...

[1972C10]

Man i Hope Your Electronics Stereo Amps Eq's Etc. Dont Get Messed up Due to flucuating Voltage That Can Be Fixed By An 1/8 Of A ScrewTurn .

[TIMSPEED]

Originally Posted by 1972C10

Man i Hope Your Electronics (Stereo Amps Eq's Etc) Dont Get Messed up Due to flucuating Voltage

What electronics? Only thing electric on this truck is the lights. But you're probably right, I should prolly idle it at 700rpm and just be done with it. But damn does it sound good at 600rpm

[1972C10]

Yeah Some of My Friends Idle Thiers Down Real Low To Make It Sound More Cammy.

You will also get More Oil Pressure At Idle With Higher RPM.

But To Each Thier Own.

[Russell]

You think 600 sounds good?

Try 500 And just to go with what Don said -- I actually fried my amp the other night due to flucutating voltages...

[TIMSPEED]

I need to wire up a voltmeter to see what my voltage is. Where should I wire it to, the batter or the alternator?

[1972C10]

Ign Power Is Where i would Wire It Your Truck Will Have a Spot On the Fuse Panel Labeled IGN UNFUSED Wire it to that with 14 or 12 gauge wire get a female terminal and 3 rings Ground the gauge to a good clean ground Scuff It with some 40 grit sandpaper then put the ground on it and it should work fine. You might put an inline Blade or glass fuse So if anything should happen Since it is an unfused Port.

[1972C10]

Oh And BTW I use a fluke Digital Voltmeter for checking alternator charge voltage at the battery or alternator ALthou a sunpro 10.99 Volt gauge will do just as good.

You might invest in a test meter with voltage test They come in handy for working on auto wireing.